Midterm Computer System (1) PDF

The Visible Computer Unitintro: ICT1001 Computer Systems 2009 1 Overview In this chapter, you will learn how to: Describe how computing devices work Identify common connectors and devices on a typical computer system Discuss features common to operating sy...

The Visible Computer Unitintro: ICT1001 Computer Systems 2009 1 Overview In this chapter, you will learn how to: Describe how computing devices work Identify common connectors and devices on a typical computer system Discuss features common to operating system software Unitintro: ICT1001 Computer Systems 2009 2 The Computing Process Computer: an electronic device that can perform calculations Typical personal computer (PC) Runs Microsoft Windows Used for various tasks Various types of computers General-purpose computing devices Specific-purpose computers Devices with computers insideUnitintro: ICT1001 Computer Systems 2009 3 The Computing Parts Hardware Physical components you can touch (e.g., keyboard and monitor) Operating system (OS) controls hardware and enables user to tell the computer what to do Example: Windows 8.1, Mac OS X, Linux User interface(UI) is software with which you can interact Graphical user interface (GUI) Unitintro: ICT1001 Computer Systems 2009 4 offers The Computing Parts (continued) Applications (programs) Allow you to do specialized tasks on a computer Type a letter. Send a message. View information about places and people. Unitintro: ICT1001 Computer Systems 2009 5 Stages The computing process is comprised of 3 stages Get data into the computer (user) Input Mouse, keyboard, touch screen Tell hardware what to do (OS) Processing Central processing unit (CPU) Show the results (OS) Output Monitor, speakers Unitintro: ICT1001 Computer Systems 2009 6 Stages (continued) Additional stages in modern computing devices Data storage Saving a permanent copy of work Network connection Means by which one computer connects to one or more other computers Unitintro: ICT1001 Computer Systems 2009 7 Why the Process Matters The computing process applies to every device. By understanding both the components involved and how they talk to each other, you can work with any computing device. Unitintro: ICT1001 Computer Systems 2009 8 Breaking It Down Steps in the whole computer process 1. Power up the computer 2. Processing parts prepare for action 3. You provide input 4. Processing parts process your command 5. Processing parts sends output 6. Output devices show results 7. Repeat Steps 3–6 (as needed) 8. Save your work 9. Power down the computer9 Unitintro: ICT1001 Computer Systems 2009 Computing Hardware Figure 3.12 PC with common peripherals Unitintro: ICT1001 Computer Systems 2009 10 Computing Hardware (continued) Figure 3.13 The business end of a PC Unitintro: ICT1001 Computer Systems 2009 11 Computing Hardware (continued) Figure 3.14 Inside the system unit Unitintro: ICT1001 Computer Systems 2009 12 Computing Hardware (continued) Figure 3.15 Portable computer (a MacBook Air) Unitintro: ICT1001 Computer Systems 2009 13 Computing Hardware (continued) Figure 3.16 Ports on a portable computer Unitintro: ICT1001 Computer Systems 2009 14  Chapter 4 Microprocessors (CPU) Unitintro: ICT1001 Computer Systems 2009 15 Overview In this chapter, you will learn how to: Identify the core components of a CPU Describe the relationship of CPUs and memory Explain the varieties of modern CPUs Select and install a CPU Troubleshoot CPUs Unitintro: ICT1001 Computer Systems 2009 16 CPU Core Components The central processing unit (CPU) works as a very powerful calculator. The CPU’s processing speed makes it look intelligent. Unitintro: ICT1001 Computer Systems 2009 17 The Man in the Box Visualize the CPU as a man in a box. He will gladly perform anything you want him to do, but he can't see or hear anything outside the box. How can you communicate with him? Figure 4.1 Imagine the CPU as a man in a box. Unitintro: ICT1001 Computer Systems 2009 18 The Man in the Box (continued) Figure 4.2 How do we talk to the Man in the Box? Unitintro: ICT1001 Computer Systems 2009 19 Talking to the Man Imagine 16 lights 8 on the inside and 8 on the outside When an inside light is on, the corresponding outside light is on. Lights may be switched on or off from either side. Communication device is called the external Figure 4.3 Cutaway of data bus (EDB). the external data bus—note that one light bulb pair is on. Unitintro: ICT1001 Computer Systems 2009 20 Talking to the Man (continued) Voltage applied to a little wire “flips the switch.” Figure 4.4 Close-up of the underside of a CPU Unitintro: ICT1001 Computer Systems 2009 21 Talking to the Man (continued) In reality, there are no bulbs, only little wires Voltage is applied or not Rather than “on-off-on-off-on-on-off-off,” represented as “10101100” Figure 4.5 Here "1" means on, "0" means off. Unitintro: ICT1001 Computer Systems 2009 22 Talking to the Man (continued) The CPU communicates with the outside world using the external data bus (EDB) Uses binary (1 is on, and 0 is off) to communicate Data lines on the bus can be switched (turned on or off) from inside or outside. Unitintro: ICT1001 Computer Systems 2009 23 Registers Inside the box are registers Represented as worktables for the Man in the Box The four general-purpose registers found in all CPUs are AX, BX, CX, and DX. Figure 4.6 The four general-purposeUnitintro: registers ICT1001 Computer Systems 2009 24 Codebook The Man in the Box needs one more tool: the codebook or instruction set. The commands are called machine language. One command is a line of code. The complete set of commands for a processor is its instruction set. Figure 4.7 CPU codebook Unitintro: ICT1001 Computer Systems 2009 25 Machine Language for the Intel 8088 10111010 The next line of code is a number. Put that number into the DX register. 01000001 Add 1 to the number already in the CX register. 00111100 Compare the value in the AX register with the next line of code. Unitintro: ICT1001 Computer Systems 2009 26 The CPU So Far Figure 4.8 The CPU so far Unitintro: ICT1001 Computer Systems 2009 27 Clock The CPU does no work until told to— even though data may be on the EDB. You need a bell to alert the Man in the Box. This is referred to as a clock wire (CLK wire) A charge on the CLK wire tells the CPU it is time to work. Figure 4.10 The CPU often needs more Figure 4.9 The CPU does nothing than one clock cycle to get a result. until activated by the clock. Unitintro: ICT1001 Computer Systems 2009 28 Clock (continued) A clock cycle is the time it takes for the CLK wire to charge. A cycle is one complete up-and-down segment of the sine wave. Every command requires at least two clock cycles. Unitintro: ICT1001 Computer Systems 2009 29 Clock Speed Clock speed is the maximum number of clock cycles the CPU can handle in a given time period. Clock speed is measured in hertz One cycle per second = 1 hertz (Hz) 1 million cycles per second = 1 megahertz (MHz) 1 billion cycles per second = 1 gigahertz (GHz) Intel 8088 ran at 4.77 MHz30 Unitintro: ICT1001 Computer Systems 2009 Clock Speed (continued) Unitintro: ICT1001 Computer Systems 2009 Figure 4.11 Where is the clock31speed? System Crystal System crystal governs CPU running speed Modern CPUs tell the motherboard the clock speed it needs, and the clock chip Figure 4.12 One of many types of system crystals Unitintro: ICT1001 Computer Systems 2009 automatically 32 System Crystal (continued) Crystal can clock a CPU with a rated speed higher than the crystal, but the CPU will operate at the slower speed of the crystal. A 1 GHz crystal can clock a 2 GHz CPU, but the CPU will operate only as fast as the crystal clock—1 GHz. Underclocking means running a CPU slower than its rated clock speed—it does not take advantage of all the power of Unitintro: ICT1001 Computer Systems 2009 the CPU. 33 Back to the External Data Bus Figure l4.13 Diagram of an Intel 8088 showing the external data bus and clock wires Unitintro: ICT1001 Computer Systems 2009 34 Memory A program is stored on the hard drive. Hard drives can’t give the CPU data at a fast enough speed, so something that stores the program and gives it to the CPU rapidly is needed. Devices that hold ones and zeros that the CPU accesses are called memory. Each line of memory has an address Used to locate the data Unitintro: ICT1001 Computer Systems 2009 35 Memory and RAM Random access memory (RAM) is organized like a spreadsheet, with each row holding eight bits (one byte). A bit is a one or a zero RAM transfers and stores data to and from the CPU in byte-sized chunks Number of bytes of RAM varies from PC to PC, with today's PCs holdingUnitintro: ICT1001 Computer Systems 2009 36 RAM as a Spreadsheet Figure 4.14 RAM as a spreadsheet Unitintro: ICT1001 Computer Systems 2009 37 DRAM Computers use dynamic RAM (DRAM) for main memory Dynamic rather than static Circuits need constant electrical charge and to be refreshed to maintain data. Figure 4.15 Typical RAM Unitintro: ICT1001 Computer Systems 2009 38  Address Bus CPU and RAM need a method to communicate, so they use the EDB. The CPU needs a helper chip—the memory controller chip (MCC) to facilitate the flow of data from RAM to the CPU. Figure 4.16 Extending the EDB Figure 4.17 The Unitintro: MCCICT1001 grabs a byte of RAM. Computer Systems 2009 39 Address Bus (continued) The address bus is a separate set of wires from the external data bus. Enables the CPU to control the MCC CPU tells the MCC which line of code it wants from RAM Figure 4.18 Address busICT1001 Computer Systems 2009 Unitintro: 40 Address Bus (continued) The number of wires in the address bus determines the maximum amount of RAM the CPU can handle. An 8088 had 20 wires, which provided 220 (1,048,576) combinations. Address space of 1,048,57 bytes or one megabyte (1 MB) Unitintro: ICT1001 Computer Systems 2009 41 Bits and Bytes Any individual 1 or 0 = a bit 4 bits = a nibble 8 bits = a byte 16 bits = a word 32 bits = a double word 64 bits = a paragraph or quad word Bits are represented as b (e.g., Kb) Bytes are represented as B (e.g., KB) Unitintro: ICT1001 Computer Systems 2009 42 Addressing Rows of RAM To determine the location in RAM First byte of RAM represented by twenty zeros (00000000000000000000) Last RAM row represented by twenty ones (11111111111111111111) Unitintro: ICT1001 Computer Systems 2009 43 Modern CPUs Developers Intel has dominated the industry with its CPUs and motherboard support chips. Modern Intel processors include Core, Pentium, Celeron, Atom, and Xeon brands. AMD has kept competition in the CPU market. While Intel holds the most market share, AMD provides quality CPUs at competitive prices. Unitintro: ICT1001 Computer Systems 2009 44 Modern CPUs (continued) Early Intel and AMD CPUs were identical; but they are no longer interchangeable. Figure 4.19 Identical Intel and AMD 486 CPUs from the early 1990s Unitintro: ICT1001 Computer Systems 2009 45 Model Names Intel and AMD differentiate product lines by using different product names, based on the target market. Table Current Intel and AMD Product Lines and 4.1 Names Market Intel AMD Mainstream and Core i7/i5/i3 A-Series, FX enthusiast desktop Budget desktop Pentium, Celeron Sempron, Athlon Portable/Mobile Core i7/i5/i3 (mobile), A-Series Core M, Atom Unitintro: ICT1001 Computer Systems 2009 46 Server Xeon Opteron Code Names Both companies use code names to keep track of different variations within models. CPUs labeled as the same model may have CPUs inside that are very different from earlier versions of that model. Figure 4.20 Same branding, different capabilities Unitintro: ICT1001 Computer Systems 2009 47 Desktop Versus Mobile Mobile devices need to consume as little electricity as possible. Less electricity consumption extends the battery charge and creates less heat. Both manufactures have created both mobile and desktop versions of their CPUs. Unitintro: ICT1001 Computer Systems 2009 48 Desktop Versus Mobile (continued) Saving energy by making the CPU run more slowly when demand is light is called throttling. Figure 4.21 Desktop vs. mobile, fight! Unitintro: ICT1001 Computer Systems 2009 49 Technology Ways CPUs have been improved Clock multipliers 64-bit processing Virtualization support Parallel execution Multicore processing Integrated memory controller (IMC) Integrated graphics processing unit (GPU) Security Unitintro: ICT1001 Computer Systems 2009 50 Clock Multipliers All modern CPUs run at some multiple of the system clock speed. In early computers, the CPU ran at the same speed as the bus. Designers discovered that the CPU could run faster than other chips on the motherboard. Technicians had to set jumpers or dual in- line package (DIP) switches on older motherboards to configure51 the multiplier. Unitintro: ICT1001 Computer Systems 2009 Clock Multipliers (continued) Figure 4.22 CPU-Z showing the clock speed, multiplier, and bus speed of a Core i7 processor hardly breaking a sweat Unitintro: ICT1001 Computer Systems 2009 52 Clock Multipliers (continued) Figure 4.23 DIP switches on a motherboard Unitintro: ICT1001 Computer Systems 2009 53 64-Bit Processing EDB and address-bus size increased in size. New technologies such as multimedia extensions (MMX) and Streaming SIMD Extensions (SSE) were added; Caused shift to 64-bit technology Most new CPUs support 64-bit processing Can run a compatible 64-bit operating Unitintro: ICT1001 Computer Systems 2009 54 64-Bit Processing (continued) CPUs also still support 32-bit processing for 32-bit operating systems, such as Linux, and 32-bit applications. Primary benefit to moving to 64-bit Supports more than 4 GB of memory – up to 16 EB (Exabyte) Unitintro: ICT1001 Computer Systems 2009 55 Virtualization Support Modern CPUs have built-in support for running more than one operating system at a time. Enables hardware-based virtualization support Makes virtualization easier and more resource-efficient Unitintro: ICT1001 Computer Systems 2009 56 Parallel Execution Modern CPUs process multiple commands and parts of commands in parallel execution. Older CPUs processed in a linear fashion. CPUs accomplish parallelism through: Multiple pipelines Dedicated cache The capability to work with multiple threads or programs at one time Unitintro: ICT1001 Computer Systems 2009 57 Pipelining Pipelining—CPU takes at least four steps (stages) Fetch: Get the data from the EDB Decode: Figure out what type of command needs to be executed Execute: Perform the calculation Write: Send the data back onto the EDB Unitintro: ICT1001 Computer Systems 2009 58 Pipelining (continued) Figure 4.24 Simple pipeline Unitintro: ICT1001 Computer Systems 2009 59 Pipelining (continued) Current CPUs have many stages in pipeline Enables CPU to run more efficiently without increasing the clock speed Current processors use multiple decode stages to reduce pipeline stalls. Current CPUs offer multiple pipelines, allowing the arithmetic logic unit Unitintro: ICT1001 Computer Systems 2009 60 Pipelining (continued) Figure 4.25 Bored integer unit Figure 4.26 Multiple pipelines Unitintro: ICT1001 Computer Systems 2009 61 Cache A cache reduces wait states by using built-in, very high-speed RAM called static RAM (SRAM). SRAM preloads as many instructions as possible. The cache on the CPU was called the L1 cache because it was used first by the CPU. The cache on the motherboard was called the L2 cache, and 62used second by Unitintro: ICT1001 Computer Systems 2009 Cache (continued) The address bus and external data bus (connecting the CPU, MCC, and RAM) were lumped into a single term called the frontside bus. The connection between the CPU and the L2 cache became known as the backside bus. Unitintro: ICT1001 Computer Systems 2009 63 Cache (continued) Figure 4.28 CPU-Z displaying the cache Figure 4.27 SRAM cache information for a Core i7 processor Unitintro: ICT1001 Computer Systems 2009 64 Cache (continued) Figure 4.29 Frontside and backside buses Unitintro: ICT1001 Computer Systems 2009 65 Multithreading CPU simulates the actions of a second processor Enhances efficiency Does not increase processing power Running multiple threads at the same time is also called simultaneous multithreading or Hyper-Threading. Unitintro: ICT1001 Computer Systems 2009 66 Multithreading (continued) Figure 4.30 Windows Task Manager with the Performance tab displayed for a system running a Hyper-Threaded Pentium 4 Unitintro: ICT1001 Computer Systems 2009 67 Multicore Processing Dual-core architecture Multiple CPUs (or cores) combined into a single chip, executing multiple threads at once Shared caches and RAM Multicore processing Multicore CPUs common today Cores work independently of the OS Differs from Hyper-Threading, in which Unitintro: ICT1001 Computer Systems 2009 the OS and applications have 68 to be Multicore Processing (continued) Unitintro: ICT1001 Computer Systems 2009 69 of a Haswell Core i7 Figure 4.31 CPU-Z showing the cache details Integrated Memory Controller Almost all current microprocessors have an integrated memory controller (IMC) Moved from the motherboard chip into the CPU to optimize the flow of information into and out from the CPU Causes different CPUs to require different types and capacities of RAM Unitintro: ICT1001 Computer Systems 2009 70 Integrated Graphics Processing Unit Video processing portion of computer tasks handled by the graphics processing unit (GPU) Can handle certain tasks much more efficiently than the standard CPU Enhances computer’s overall performance while reducing energy use, size, and cost Ideal for mobile devices Unitintro: ICT1001 Computer Systems 2009 71 Security NX bit technology in all modern processors Enables CPU to protect certain sections of memory Stops malicious attacks from getting to essential operating system files Known by different terms Microsoft – Data execution prevention (DEP) Intel – XD bit (eXecute Disable) AMD – Enhanced Virus ProtectionUnitintro: ICT1001 Computer Systems 2009 72 Security (continued) Figure 4.32 DEP in Windows 8.1 Unitintro: ICT1001 Computer Systems 2009 73 Selecting and Installing CPUs Techs face challenges of: Selecting the proper CPU Installing several types of processors Troubleshooting Unitintro: ICT1001 Computer Systems 2009 74 Selecting a CPU Select a CPU the motherboard can support Intel or AMD If buying a motherboard with a CPU: Select CPU appropriate for the intended purpose Determine the type of socket on the motherboard Check motherboard documentation or Unitintro: ICT1001 Computer Systems 2009 manufacturer’s web site 75 Selecting a CPU (continued) Figure 4.33 Supported processors and socket type Unitintro: ICT1001 Computer Systems 2009 76 Selecting a CPU (continued) Table 4.2 Intel-based Sockets Socket CPU LGA 7751 Pentium 4, Celeron, Pentium 4 Extreme Edition, Core 2 Duo, Core 2 Quad, Xeon, and many others LGA 11562 Core i3/i5/i7, Pentium, Celeron, Xeon LGA 11553 Core i3/i5/i7, Pentium, Celeron, Xeon LGA 13664 Core i7, Xeon, Celeron LGA 20115 Core i7, Core i7 Extreme Edition, Xeon LGA 11506 Core i3/i5/i7, Pentium, Celeron, Xeon LGA 11517 Core i3/i5/i7, Pentium, Celeron, Xeon Unitintro: ICT1001 Computer Systems 2009 77 Selecting a CPU (continued) Table 4.3 AMD-based Sockets Socket Pins CPU AM31 941 Phenom II, Athlon II, Sempron, Opteron AM3+ 942 FX FM1 905 A-Series2 FM2 904 A-Series FM2+ 906 A-Series G34 1974 Opteron C32 1207 Opteron Unitintro: ICT1001 Computer Systems 2009 78 Installation Issues Pay careful attention to: CPU pins Power supply Adequate cooling Consider whether to leave CPU at stock settings or overclock it Unitintro: ICT1001 Computer Systems 2009 79 Socket Types Socket types Intel processors use a land grid array (LGA) package AMD CPU pins align with socket holes—a pin grid array (PGA) CPUs and sockets keyed to help prevent misalignment and incorrect insertion Zero Insertion Force (ZIF) sockets Unitintro: ICT1001 Computer Systems 2009 80 Socket Types (continued) Figure 4.35 AMD-based socket without pins Figure 4.34 Intel-based socket with pins Figure 4.36 Underside and top of a CPU Unitintro: ICT1001 Computer Systems 2009 81 Socket Types (continued) Figure 4.37 Moving the release arm Figure 4.38 Fully opened socket Unitintro: ICT1001 Computer Systems 2009 82 Cooling CPUs heat up due to electrical power consumption (wattage). Most CPUs use a combination of heat sink and fan assembly to keep them within normal operating temperatures. Figure 4.39 Intel stock heat sink and fan assembly Unitintro: ICT1001 Computer Systems 2009 83 Cooling (continued) OEM CPU coolers Heat sink and fan assemblies included with a retail-boxed CPU Specialized CPU coolers Third-party heat-sink and fan assemblies for a variety of CPUs Usually exceed the OEM heat sinks in the amount of heat they dissipate Unitintro: ICT1001 Computer Systems 2009 84 Cooling (continued) Figure 4.40 Cool retail heat sink Unitintro: ICT1001 Computer Systems 2009 85 Cooling (continued) Liquid cooling works by running some liquid (usually water) through a metal block that sits on top of the CPU, absorbing heat. Apply a small amount of thermal paste (thermal compound, heat dope, or nasty silver goo) to the CPU before attaching the heat sink. Applying too much or too little can cause Unitintro: ICT1001 Computer Systems 2009 the CPU to overheat and 86fail. Cooling (continued) Figure 4.41 Liquid-cooled CPU Unitintro: ICT1001 Computer Systems 2009 87 Cooling (continued) Figure 4.42 CPU fan power header on motherboard Unitintro: ICT1001 Computer Systems 2009 88 Cooling (continued) Figure 4.43 Applying thermal Figure 4.44 AMD stock heat-sink paste and fan assembly Unitintro: ICT1001 Computer Systems 2009 89 Cooling (continued) Figure 4.45 Heat-sink and fan assembly mounted to motherboard with screws Unitintro: ICT1001 Computer Systems 2009 90 Overclocking For the CPU to work, the motherboard speed, multiplier, and voltage must be set properly. Motherboard uses the CPUID functions to set these options automatically. Some motherboards enable you to adjust these settings. Some people intentionally run their systems at clock speeds higher than Unitintro: ICT1001 Computer Systems 2009 the CPU was rated, a process 91 called Overclocking (continued) Intentional overclocking of a CPU immediately voids most warranties. Can cause system instability, lockups, frequent reboots, or damage, and may destroy CPU Overclocking is done through jumpers, CMOS settings, or software configuration. Usually involves increasing the bus speed Unitintro: ICT1001 Computer Systems 2009 for 92 Overclocking (continued) Figure 4.46 Manually overriding CPU settings in theUnitintro: system setup utility ICT1001 Computer Systems 2009 93 Overclocking (continued) In case you need to go back to CMOS defaults, use the CMOS clear jumper setting from the motherboard manual. Unitintro: ICT1001 Computer Systems 2009 944.47 CMOS-clear jumper Figure Troubleshooting CPUs Overheating This condition can cause system to not start or to lockup. Newer CPUs will usually shut themselves down before overheating. Most heating problems are due to faulty installation or environmental issues. Catastrophic failure Less common than overheating Unitintro: ICT1001 Computer Systems 2009 95 Symptoms of Overheating Problems to address with a faulty installation. Too much thermal paste can impede the flow of heat from the CPU to the heat sink. Not enough thermal paste can cause the CPU to heat up and shut down. Failure to connect fan power to the motherboard can cause CPU to heat up and shut down. Unitintro: ICT1001 Computer Systems 2009 96 Catastrophic Failure Displays a proprietary crash screen Window’s Blue Screen of Death (Windows Stop error) Spinning pinwheel on Mac OS X May cause PC to shut down or go black May burn up components Unitintro: ICT1001 Computer Systems 2009 97 Catastrophic Failure (continued) Figure 4.48 Blue Screen of Death Unitintro: ICT1001 Computer Systems 2009 98 Beyond A+ Intel Core M Very low power (4.5 watts) Compared with mobile version of Core i7 at 57 watts Modest processing power – falls between Atom and mobile Core i3 Manufacturers can skip the fan Running in Apple MacBook Unitintro: ICT1001 Computer Systems 2009 99 RAM (Memory) Unitintro: ICT1001 Computer Systems 2009 100 Overview In this chapter, you will learn how to: Identify the different types of DRAM packaging Explain the varieties of RAM Select and install RAM (part of assembly lab) Perform basic RAM troubleshooting Unitintro: ICT1001 Computer Systems 2009 101 Program Execution Program code is copied from your hard drive into RAM before it is executed. Dynamic Random Access Memory (DRAM) Figure 5.1 Mass storage holds programs, but programs need to run in RAM. Unitintro: ICT1001 Computer Systems 2009 102 DRAM Sticks (continued) Single inline memory modules (SIMM) You must get the correct stick(s) for a particular motherboard. Check the motherboard manual for type of module and amount of RAM you can install. Figure 5.7 A 72-pin SIMM Unitintro: ICT1001 Computer Systems 2009 103 DRAM Sticks (continued) Current RAM is 32 bits wide and 64 bits wide. The MCC keeps track of the physical location of the RAM. Figure 5.8 The MCC knows the real location of the DRAM. Unitintro: ICT1001 Computer Systems 2009 104 Consumer RAM Modern DRAM modules come in sizes much wider than a byte. RAM is described by the total capacity in bytes. For example, 4-GB sticks Unitintro: ICT1001 Computer Systems 2009 105 Types of RAM - Overview New DRAM technologies are driven by newer, wider, and faster CPUs and MCCs. Types of RAM: Synchronous DRAM (SDRAM) Rambus DRAM (RDRAM) Double data rate SDRAM (DDR SDRAM) DDR2 and DDR3 DDR3L/DDR3U DDR4 Unitintro: ICT1001 Computer Systems 2009 106 SDRAM Synchronized with the system clock Came on a stick called a dual inline memory module (DIMM) Came in a wide variety of pin sizes with early DIMMs 168-pin version common on desktops Laptop DIMMs in 68-pin, 144-pin, or 172- pin micro-DIMM packages Small-outline DIMM (SO-DIMM) of 72 pins, 144 pins, or 200 pins also for laptops Unitintro: ICT1001 Computer Systems 2009 107 SDRAM (continued) To use SDRAM, you need a computer designed for it. Each open slot is called a bank. Instead of an access speed, it has a clock speed measured in MHz. Common speeds were 66, 75, 83, 100, and 133 MHz. Unitintro: ICT1001 Computer Systems 2009 108 RDRAM RDRAM could support speeds on the frontside bus of up to 800 MHz. Needed for the quad-pumped CPUs Originally thought to be the next best thing, RDRAM suffered delays in manufacturing and was significantly more expensive than SDRAM. A stick of RDRAM was called a RIMM. Doesn’t stand for anything – SIMMs, DIMMs, and RIMMS rhyme Unitintro: ICT1001 Computer Systems 2009 109 DDR SDRAM Fast RAM supported by AMD and other manufacturers Doubles the throughput over SDRAM (makes two processes for each clock cycle) Commonly referred to as DDR, DDR RAM, and DDRAM Comes in 184-pin DIMMs for desktops Cannot insert RAM in incorrect slots Slots keyed with guide notches 110 Unitintro: ICT1001 Computer Systems 2009 DDR SDRAM (continued) DDR speed rating and PC speed rating are based on clock speed. Base clock speed is 100 MHz to 300 MHz with the DDR speed rating double the clock speed. To determine the PC speed rating (bytes per second), multiply the DDR speed (MHz) by 8. For example, a chip with a clock speed of 200 MHz has a DDR speed rating of 400 (200 MHz ×2) and would 111be referred to Unitintro: ICT1001 Computer Systems 2009 DDR SDRAM (continued) Table DDR Speeds 5.1 Clock Speed DDR Speed PC Speed Rating Rating 100 MHz DDR-200 PC-1600 133 MHz DDR-266 PC-2100 166 MHz DDR-333 PC-2700 200 MHz DDR-400 PC-3200 217 MHz DDR-433 PC-3500 233 MHz DDR-466 PC-3700 250 MHz DDR-500 PC-4000 275 MHz DDR-550 PC-4400 Unitintro: ICT1001 Computer Systems 2009 300 MHz DDR-600 112 PC-4800 DDR SDRAM (continued) Dual-channel architecture uses two sticks of RDRAM together to increase throughput. Dual-channel DDR requires two identical sticks of DDR, and the sticks must snap into paired slots. Unitintro: ICT1001 Computer Systems 2009 113 DDR SDRAM (continued) Figure 5.14 A motherboard showing the four RAM slots. By populating the same color slots with identical RAM, you can run in dual-channel mode. Unitintro: ICT1001 Computer Systems 2009 114 DDR2 DDR2 is DDR RAM with improvements in electrical characteristics to run faster on less power. Speed increase comes by clock doubling the input/output circuits on the chips. DDR2 uses 240-pin DIMM (not compatible with DDR DIMM). Figure 5.15 240-pin Unitintro:DDR2 DIMMSystems 2009 ICT1001 Computer 115 DDR2 (continued) Table 5.2 DDR2 Speeds Core RAM Clock DDR I/O DDR2 Speed PC Speed Speed Speed Rating Rating 200 MHz 100 MHz DDR2-400 PC-3200 266 MHz 133 MHz DDR2-533 PC-4200 333 MHz 166 MHz DDR2-667 PC-5300 400 MHz 200 MHz DDR2-800 PC-6400 533 MHz 266 MHz DDR2-1066 PC-8500 Unitintro: ICT1001 Computer Systems 2009 116 DDR3 DDR3 has higher speeds, more efficient architecture, and 30 percent lower power consumption than DDR2 RAM. It uses 240-pin DIMM (not compatible with DDR2). DDR3 doubles the buffer of DDR2 from 4 bits to 8 bits. Some DDR3 modules also include XMP, or extended memory profile. Unitintro: ICT1001 Computer Systems 2009 117 DDR3 (continued) Some chipsets that support DDR3 also support a feature called triple- channel architecture or quad-channel architecture. Works a lot like dual-channel before it, but with three or four sticks of RAM instead of two Triple-channel memory is: Supported by Intel’s LGA 1366 platform Not supported by AMD processors Unitintro: ICT1001 Computer Systems 2009 118 DDR3 (continued) DDR3 I/O speeds are quadruple the clock speeds Due to increased buffer size Figure 5.16 DDR2 DIMM on top of a DDR3 DIMM Unitintro: ICT1001 Computer Systems 2009 119 DDR3 (continued) Table 5.3 DDR3 Speeds Core RAM Clock DDR I/O DDR3 Speed PC Speed Speed Speed Rating Rating 400 MHz 100 MHz DDR3-800 PC3-6400 533 MHz 133 MHz DDR3-1066 PC3-8500 667 MHz 166 MHz DDR3-1333 PC3-10667 800 MHz 200 MHz DDR3-1600 PC3-12800 933 MHz 233 MHz DDR3-1866 PC3-14900 1066 MHz 266 MHz DDR3-2133 PC3-17000 1200 MHz 300 MHz DDR3-2400 PC3-19200 Unitintro: ICT1001 Computer Systems 2009 120 DDR3L/DDR3U DDR3L is a low voltage version of DDR3. It provides a substantial cost savings when used in massive RAM applications. DDR3L runs at 1.35 volts. DDR3U is ultra-low voltage and runs at 1.25 volts. The DIMM is slot-compatible with DDR3. Unitintro: ICT1001 Computer Systems 2009 121 DDR4 DDR4 offers higher density and lower voltages than DDR3, and can handle faster data transfer rates. Runs at only 1.2 volts Uses 288-pin DIMM Not backward compatible with DDR3 slots Unitintro: ICT1001 Computer Systems 2009 122 DDR4 (continued) Table 5.4 DDR4 Varieties Core RAM Clock Bandwidth DDR4 Speed PC Speed Speed Rating Rating 1600 MT/s 200 MHz DDR4-1600 PC4-12800 2133 MT/s 266 MHz DDR4-2133 PC4-17000 2400 MT/s 300 MHz DDR4-2400 PC4-19200 3200 MT/s 400 MHz DDR4-3200 PC4-25600 Unitintro: ICT1001 Computer Systems 2009 123 RAM Variations Double-sided DIMMs Every type of RAM comes in one of two types: single-sided RAM and double- sided RAM. Some motherboards can’t use double- sided sticks. Latency Numbers reflect how many ticks of the system clock it takes before the RAM responds. RAM with a lower latency—such Unitintro: ICT1001 Computer Systems 2009 124 as CL6— RAM Variations (continued) Figure 5.17 Double-sided DDR SDRAM Unitintro: ICT1001 Computer Systems 2009 125 RAM Variations (continued) Parity and ECC Parity RAM allows the computer to detect whether an error occurred in the reading or writing of data in memory. Error correction code (ECC) RAM is an improvement over parity, detecting as well as correcting errors. Always slower than non-ECC RAM because of the extra calculations required Used only on high-end systems Unitintro: ICT1001 Computer Systems 2009 126 RAM Variations (continued) Figure 5.19 Ancient parity RAM stick Unitintro: ICT1001 Computer Systems 2009 127 RAM Variations (continued) Registered and buffered memory Registered RAM (or buffered RAM) refers to a small register installed on some memory modules to act as a buffer between the DIMM and the memory controller. The motherboard will use either buffered or unbuffered RAM (typical consumer RAM), not both. Unitintro: ICT1001 Computer Systems 2009 128 Working with RAM Adding more RAM almost always improves overall system performance, processing speed, and stability To obtain desired results: Determine whether insufficient RAM is the cause of system problems. Pick the proper RAM for the system. Use good installation practices such as keeping RAM sticks in antistatic packaging and following strict ESD Unitintro: ICT1001 Computer Systems 2009 practices. 129 Working with RAM (continued) What's wrong with this picture? Unitintro: ICT1001 Computer Systems 2009 130 Do You Need More RAM? Two symptoms show the need for more RAM: General system sluggishness Excessive hard drive accessing Programs take forever to load. Running programs seem to stall and move more slowly than you would like. Unitintro: ICT1001 Computer Systems 2009 131 Do You Need More RAM? (continued) Virtual memory is a portion of the hard drive used as an extension of RAM. A portion of an HDD or SSD is set aside as a page file or swap file. When the PC starts running out of real RAM because you've loaded too many programs, the system swaps programs from RAM to the page file, opening more space for programs currently active. Disk thrashing occurs when Unitintro: ICT1001 Computer Systems 2009 132 the operating Do You Need More RAM? System RAM recommendations Microsoft’s system RAM recommendations for various Windows operating systems are very low. Consider installing additional memory to reach the reasonable minimum for solid performance or if you are a power user. 32-bit Windows: 2GB to 4GB 64-bit Windows: 4GB to 16+ GB OS X: 4GB to 8+ GB Linux: many distros get by on Unitintro: very minimal ICT1001 Computer Systems 2009 133 system requirements Do You Need More RAM? (continued) Determining current RAM capacity Uses the System Control Panel applet (property sheet) ReadyBoost Featured in Windows Vista and later versions Enables use of flash media devices as dedicated virtual memory (faster then HDD) Unitintro: ICT1001 Computer Systems 2009 134 Do You Need More RAM? (continued) Figure 5.28 Mike has a lot of RAM! Unitintro: ICT1001 Computer Systems 2009 135 Do You Need More RAM? (continued) Figure 5.29 Performance tab in Windows 8.1 Task Manager Unitintro: ICT1001 Computer Systems 2009 136 Do You Need More RAM? (continued) Figure 5.30 Dedicating a flash drive to ReadyBoost to enhance system performance. Unitintro: ICT1001 Computer Systems 2009 137 Getting the Right RAM To achieve the perfect RAM upgrade: Determine the optimum amount of RAM to install and then get the right RAM for the motherboard. Information inside the case and in the motherboard manual Example: You can’t put DDR4 into a system that can only handle DDR3 SDRAM. RAM limits are specified in 138 the Unitintro: ICT1001 Computer Systems 2009 Getting the Right RAM (continued) Mix and match at your peril. Different RAM sizes aren’t always handled well in motherboards. It’s best to choose RAM sticks that match technology, capacity, and speed. It’s best not to mix speeds. You can place higher-rated RAM into a slower-rated motherboard, but the RAM will work at the slower rate of the motherboard. Unitintro: ICT1001 Computer Systems 2009 139 Installing DIMMs This is an easy process even for non- techie folks. Line up the notches and place the stick in the slot. Push down and the tabs will lock into position. Unitintro: ICT1001 Computer Systems 2009 140 Installing DIMMs (continued) Serial Presence Detect (SPD) technology detects and automatically sets up installed DIMM. When a PC boots, it queries the SPD chip so that the MCC knows how much RAM is on the stick, how fast it runs, and other information. Any program can query the SPD chip to obtain RAM information. CPU-Z is a program that displays some of Unitintro: ICT1001 Computer Systems 2009 141 Installing DIMMs (continued) Figure 5.32 Inserting a DIMM Fi5.33 SPD chip on a stick gure Unitintro: ICT1001 Computer Systems 2009 142 Installing DIMMs (continued) Figure 5.34 CPU-Z showing RAM information Unitintro: ICT1001 Computer Systems 2009 143 Installing DIMMs (continued) The RAM count Older systems display the RAM count during the initial boot sequence. If you installed the RAM correctly, the RAM count on the PC reflects the new value. If the RAM value stays the same, you probably have installed the RAM in a slot the motherboard doesn’t want you to use. Unitintro: ICT1001 Computer Systems 2009 144 Installing DIMMs (continued) Figure 5.35 Hey, where’s the rest of my RAM?! Figure 5.36 RAM count after proper insertion of DIMMs Unitintro: ICT1001 Computer Systems 2009 145 Installing SO-DIMMs in Laptops For years, laptops had proprietary RAM packages, making this difficult. However, the acceptance of SO-DIMMs over the years has made it much easier. First, power off, unplug, and remove the battery pack—follow ESD procedures. Identify the access point for the SO- DIMM. This is usually either under the keyboard Unitintro: ICT1001 Computer Systems 2009 146 Installing SO-DIMMs in Laptops (continued) Figure 5.37 A RAM access panel Figure 5.38 Snapping in a SO-DIMM on a laptop Unitintro: ICT1001 Computer Systems 2009 147 Troubleshooting RAM “Memory” errors show up in a variety of ways on modern systems, including: Parity errors ECC error messages System lockups Page faults Other error screens Parity error types include: Real parity errors Unitintro: ICT1001 Computer Systems 2009 148 Troubleshooting RAM (continued) Memory errors can include: Page Fault – not necessarily RAM problems Non-maskable interrupt (NMI) – panic button inside the PC Manifests as proprietary crash screen—Blue Screen of Death (BSoD) in Windows Vista and Windows 7 and the pinwheel of death in Mac OS X Not all intermittent errors are RAM- related. Unitintro: ICT1001 Computer Systems 2009 Dying power supply, electrical 149 interference, Testing RAM Use a RAM-testing device. Replace one stick at a time until problems disappear. Run a software-based tester on the RAM. Windows Memory Diagnostic tool is included with Windows 7 and later. Memtest86+ software from memtest.org is another example. Unitintro: ICT1001 Computer Systems 2009 150 Testing RAM (continued) Figure 5.40 Memtest86+ in action Unitintro: ICT1001 Computer Systems 2009 151 Motherboards Unitintro: ICT1001 Computer Systems 2009 152 Overview In this chapter, you will learn how to: Explain how motherboards work Recognize modern expansion buses Upgrade and install motherboards Troubleshoot motherboard problems Unitintro: ICT1001 Computer Systems 2009 153 Layers of the PCB The motherboard provides the foundation for the personal computer. The motherboard contains wires called traces. Without the motherboard, you have no PC. Unitintro: ICT1001 Computer Systems 2009 154 How Motherboards Work Form factor determines: Size of the motherboard General location of components and parts Chipset determines: Type of processor and RAM supported Built-in components determine: The core functions of the system Unitintro: ICT1001 Computer Systems 2009 155 Form Factors Form factor defines: Size, shape, and layout of the motherboard Determines the type of case you can use Power supply interface type How the air moves around in the case For upgrades and recommendations, you need to know form factors. Unitintro: ICT1001 Computer Systems 2009 156 AT Form Factor IBM invented the AT form factor in the early 1980s. Lasted through mid-1990s Currently obsolete Lacked external ports – keyboard port the only dedicated connector Figure 7.3 AT- style motherboard Unitintro: ICT1001 Computer Systems 2009 157 The AT Form Factor (continued) Figure 7.4 AT motherboard (bottom) Figure 7.5 Keyboard connector on and Baby AT motherboard (top) the back of an AT motherboard Unitintro: ICT1001 Computer Systems 2009 158 ATX Form Factor ATX was created in 1995. ATX had many ports accessible from rear of PC including mini-DIN. CPU and RAM are placed to provide easier access. RAM was closer to Northbridge and CPU for better performance. Unitintro: ICT1001 Computer Systems 2009 159 ATX Form Factor (continued) Figure 7.6 Early ATX motherboard Unitintro: ICT1001 Computer Systems 2009 160 ATX Form Factor (continued) Figure 7.7 ATX ports Figure 7.8 AT (left) and ATX (right) motherboards for quick visual comparison Unitintro: ICT1001 Computer Systems 2009 161 ATX Form Factor (continued) MicroATX 30 percent smaller size than standard ATX Features standard ATX connections Fits in standard ATX case or microATX cases FlexATX Smallest motherboards in the ATX standard Mostly obsolete 162 Unitintro: ICT1001 Computer Systems 2009 ITX VIA Technologies created Small Form Factor (SFF) motherboards—called the ITX ITX did not last long, but three smaller sizes populate the SFF market today: Mini-ITX, Nano-ITX, and Pico-ITX. Mini-ITX is the largest and most popular of the three ITX form factors. It measures 6.7 by 6.7 inches. It competes head to head withUnitintro: theICT1001 virtually Computer Systems 2009 163 identical microATX. ITX (continued) Nano-ITX and Pico-ITX Nano-ITX measures 4.7 by 4.7 inches. Pico-ITX is 3.8 by 2.8 inches. These form factors are commonly used on embedded and specialty systems. One of greatest benefits of these SSF motherboards is very low power requirements. Produce very low heat Can use passive cooling systems, making Unitintro: ICT1001 Computer Systems 2009 164 Proprietary Form Factors Unique to a specific company Do not follow standards and require upgrades and service from authorized dealers Can contain riser cards—part of the motherboard separated from the main one but connected by a cable Unitintro: ICT1001 Computer Systems 2009 165 Chipset A chipset determines: The processor type Type and capacity of RAM The internal and external devices supported by the motherboard It serves as the electronic interface through which the CPU, RAM, and I/O devices interact. Chipsets were originally comprised of two primary chips: 166 Unitintro: ICT1001 Computer Systems 2009 Chipset (continued) Northbridge Helps the CPU work with RAM (on older systems) Communicates with video on newer AMD systems Southbridge Handles expansion devices and mass storage drives Super I/O chip Provides support for legacy Unitintro: ICT1001 Computer Systems 2009 167 devices and Chipset (continued) Figure 7.14 Driver disc for ASUS motherboard Figure 7.13 Super I/O chip on ASUS motherboard Unitintro: ICT1001 Computer Systems 2009 168 Chipset (continued) Unitintro: ICT1001 Computer Systems 2009 Figure 7.15 Schematic of a modern 169 chipset Motherboard Components Not all chipset features may be supported with ports (for cost savings). Some motherboards may have additional chips to support: USB/FireWire Sound Networking Video Unitintro: ICT1001 Computer Systems 2009 170 Motherboard Components (continued) Figure 7.17 Front USB and FireWire Figure 7.16 USB/FireWire dongle drive bay device Unitintro: ICT1001 Computer Systems 2009 171 Motherboard Components (continued) Case fan support Every motherboard has a CPU fan power connector, usually a four-wire connector that also supports three-wire fans. Some motherboards offer one or more fan power connectors for case fans, usually three-wire connectors. The case fans plugged into the motherboard can be monitored and controlled in Windows. Unitintro: ICT1001 Computer Systems 2009 172 Expansion Bus The original IBM PC had slots built into the motherboard called expansion slots for adding new functions to the PC. The slots and accompanying wires on the first and the latest PCs are called the expansion bus. Unitintro: ICT1001 Computer Systems 2009 173 Structure and Function of the Expansion Bus Every device in the computer connects to the external data bus and the address bus Applies whether a device is soldered to the motherboard or snapped into a socket Expansion slots connect to the rest of the PC through the chipset. The chipset provides an extension of Unitintro: ICT1001 Computer Systems 2009 the address data bus to174the expansion Structure and Function of the Expansion Bus (continued) Figure 7.18 Expansion slots connecting Figure 7.19 Expansion slots connecting to Southbridge to Northbridge Unitintro: ICT1001 Computer Systems 2009 175 Structure and Function of the Expansion Bus (continued) Unitintro: ICT1001 Computer Systems 2009 Figure 7.20 Expansion slots connecting to both176 Northbridge and Southbridge Structure and Function of the Expansion Bus (continued) Clock crystals control CPU and chipset speeds, but the expansion slots run at a much slower speed than the frontside bus. The expansion bus crystal, which controlled the part of the external data bus connected to the expansion bus Made expansion slot timing possible so a card did not have to be produced for each clock speed. Unitintro: ICT1001 Computer Systems 2009 177 Structure and Function of the Expansion Bus (continued) Figure 7.21 The system crystal sets the speed. Figure 7.22 Function of system and expansion bus crystals Unitintro: ICT1001 Computer Systems 2009 178 PCI 1990s: Intel introduced the Peripheral Component Interconnect (PCI) bus architecture. Released it into the public domain PCI provided a wider, faster, more flexible alternative than any previous expansion bus. The original PCI bus was 32 bits wide and ran at 33 MHz. Unitintro: ICT1001 Computer Systems 2009 179 PCI (continued) PCI could coexist with other expansion buses. Enabled users to use more than one type of expansion card and allowed them to migrate to PCI slowly PCI devices were/are self-configuring, leading to the plug-and-play (PnP) standard. PCI had a powerful burst-mode Unitintro: ICT1001 Computer Systems 2009 feature that enabled very 180 efficient PCI (continued) Figure 7.23 PCI expansion bus slots. Unitintro: ICT1001 Computer Systems 2009 181 AGP Intel introduced a specialized, video- only version of PCI called the Accelerated Graphics Port (AGP). Addressed slow, substandard graphics AGP slot is a PCI slot that has a direct connection to the Northbridge. AGP slots are only for video cards. Unitintro: ICT1001 Computer Systems 2009 182 PCI-X PCI Extended (PCI-X) is a high-speed alternative to PCI. 64-bit AGP slots supported 32-bit PCI cards for backward compatibility and was easy to upgrade. It supported native 64-bit PCI-X cards. The PCI-X 2.0 standard featured four speed grades (measured in MHz): PCI-X 66, PCI-X 133, PCI-X 266, and PCI-X 533 Unitintro: ICT1001 Computer Systems 2009 183 Mini-PCI Mini-PCI put PCI into laptops Designed to use low power and to lie flat. Figure 7.26 Tiny card in Mini-PCI slot. See the contacts at the bottom of the picture? Unitintro: ICT1001 Computer Systems 2009 184 PCI Express PCI Express (PCIe) is the latest, fastest, and most popular expansion bus in use today. PCI Express is still PCI. Uses a point-to-point serial connection instead of PCI’s shared parallel communication—does not share its bus PCIe device has its own direct connection (a point-to-point Unitintro: ICT1001 Computer Systems 2009 connection) to the Northbridge. 185 PCI Express (continued) PCIe has no overhead issues with data order checking, as all bits arrive serially. PCIe uses one wire for sending and one for receiving—the pair of wires called a lane. Can use 1, 2, 4, 8, 12, or 16 lanes to achieve a maximum theoretical bandwidth of 128 GTps (gigatransfers per second) Unitintro: ICT1001 Computer Systems 2009 186 PCI Express (continued) Most common PCIe slot is the 16-lane (×16) version most commonly used for video cards. Figure 7.27 PCIe ×16 slot (black) with PCI slots (blue) Figure 7.28 PCIe ×1 slot (top) Unitintro: ICT1001 Computer Systems 2009 187 Installing Expansion Cards Installing an expansion card requires at least four steps. Step 1: knowledge Learn about the device you plan to install. Does it work with your system? Does it have drivers for your OS? Get documentation from the vendor (Web site, manual, etc.). Check the Microsoft Web188 site for lists of Unitintro: ICT1001 Computer Systems 2009 Installing Expansion Cards (continued) Step 2: physical installation Take steps to avoid damaging the card or the motherboard—use ESD precautions/procedures. Always unplug the PC before inserting an expansion card. Hold the card only by its edges without touching the slot connectors or any board components. Place the card firmly and completely into an available expansion slot. Unitintro: ICT1001 Computer Systems 2009 189 Installing Expansion Cards (continued) Unitintro: ICT1001 Computer Systems 2009 190a card Figure 7.30 Where to handle Installing Expansion Cards (continued) Figure 7.31 Always secure all cards properly. Unitintro: ICT1001 Computer Systems 2009 191 Installing Expansion Cards (continued) Figure 7.32 Properly seated expansion card; note the tight fit between case and mounting bracket and the evenness of the card in the slot. Unitintro: ICT1001 Computer Systems 2009 192 Installing Expansion Cards (continued) Step 3: device drivers Always check the manufacturer’s Web site for the best possible driver. Ensure you have the correct hardware model and version number for the driver you want to install. In almost all cases, you should install the device driver after you install the device. Some cards require you to remove old drivers of the same type before you install the new device. Some will automatically be removed when new drivers are installed. Unitintro: ICT1001 Computer Systems 2009 193 Installing Expansion Cards (continued) Figure 7.33 Part of a Readme file showing the driver version Unitintro: ICT1001 Computer Systems 2009 194 Installing Expansion Cards (continued) Figure 7.34 Uninstalling a device Unitintro: ICT1001 Computer Systems 2009 195 Installing Expansion Cards (continued) Windows Hardware Certification Program Rigorous testing program provided by Microsoft Unsigned drivers The last of the 32-bit versions of Windows supported these drivers that had not gone through the Windows Certification Program. Windows displayed a warning Unitintro: message for ICT1001 Computer Systems 2009 196 Installing Expansion Cards (continued) Figure 7.36 Unsigned driver warning Unitintro: ICT1001 Computer Systems 2009 197 Installing Expansion Cards (continued) Installing the new driver Two ways to install a new driver Using the installation disc directly Using the Add Hardware Wizard in the Control Panel – phased out after Vista Driver rollback Allows rollback to previous drivers after an installation or driver upgrade Accessed in Device Manager Driver installation and maintenance Unitintro: ICT1001 Computer Systems 2009 often requires proper Windows 198 Installing Expansion Cards (continued) Figure 7.37 Installation menu Unitintro: ICT1001 Computer Systems 2009 199 Installing Expansion Cards (continued) Figure 7.38 Driver rollback feature Unitintro: ICT1001 Computer Systems 2009 200 Installing Expansion Cards (continued) Step 4: verify The last step in the installation process is to inspect the results of the installation and verify that the device works properly. Open Device Manager and verify that Windows sees the device. Test the functionality of the device. Does the device do what it is supposed to do? Unitintro: ICT1001 Computer Systems 2009 201 Troubleshooting Expansion Cards Properly installed cards rarely cause trouble. Botched installations produce headaches. First sign of trouble is that the card does not work as expected. Primary troubleshooting process is to reinstall—after checking Device Manager. Unitintro: ICT1001 Computer Systems 2009 202 Troubleshooting Expansion Cards (continued) Device Manager provides the first diagnostic and troubleshooting tool in Windows. After you install a new device, Device Manager gives you many clues if something has gone wrong. If Device Manager does not recognize the new device, one of two problems exist: Device is physically damaged. There is a problem with the device driver. Unitintro: ICT1001 Computer Systems 2009 203 Troubleshooting Expansion Cards (continued) Device manager error codes usually indicate the trouble: A black “!” on a yellow triangle indicates that a device is missing, that Windows does not recognize a device, or that there’s a device driver problem. A device may still work even while producing this error. A black downward-pointing arrow on a white field in indicates a disabled device. This usually points to a device that’s either been turned off manually or is damaged. A device producing this error will not work. Unitintro: ICT1001 Computer Systems 2009 204 Troubleshooting Expansion Cards (continued) Figure 7.40 An "!" in Device Manager, indicating a problem with the selected device Unitintro: ICT1001 Computer Systems 2009 205 Troubleshooting Expansion Cards (continued) Correcting a Device Manager error First, double-check the device’s connections. Second, try reinstalling the driver with the Update Driver button. Also, check that the device isn’t disabled. Unitintro: ICT1001 Computer Systems 2009 206 Troubleshooting Expansion Cards (continued) Figure 7.41 Updating the driver Unitintro: ICT1001 Computer Systems 2009 207 Upgrading and Installing Motherboards Choosing the motherboard and case First, determine what motherboard you need. Is your CPU supported? How much RAM do you intend to install? Look for a high-quality manufacturer, e.g., ASUS, BIOSTAR, DFI, GIGABYTE, Intel, or MSI. Second, get a form factor that works with your case. Third, be sure you obtain the motherboard book. Unitintro: ICT1001 Computer Systems 2009 208 Installing a Motherboard Remove all the cards. Remove obstructing drives. Remove the power supply (only if necessary). Unscrew the old motherboard. The motherboard mounts to the case with small connectors called standoffs. Unitintro: ICT1001 Computer Systems 2009 209 Installing a Motherboard (continued) Figure 7.44 Standout in a case, ready for the motherboard. Unitintro: ICT1001 Computer Systems 2009 210 Installing a Motherboard (continued) Check/adjust the location of the standoffs. Connect the LEDs, buttons, and front- mounted ports on the front of the box. Install the motherboard into the case fully. With CPU and RAM properly installed, install the hard drive(s), power supply, etc. Unitintro: ICT1001 Computer Systems 2009 211 Installing a Motherboard (continued) Test the power; make sure POST takes place. If you have a POST card, you can also use it to test the motherboard. If you don’t have a POST card, connect a video card and monitor to the board to see if it runs the BIOS check successfully. Turn the computer off and unplug it before adding other components or reassembling the case. 212 Unitintro: ICT1001 Computer Systems 2009 Installing a Motherboard (continued) If there’s no power at all, check the power connectors to the motherboard. If there’s power for the motherboard and fans but nothing on the screen, check the seating of RAM, video card, and finally the CPU. Unitintro: ICT1001 Computer Systems 2009 213 Installing a Motherboard (continued) Figure 7.45 Motherboard wire connections labeled on the Figure 7.46 Sample of case wires motherboard Unitintro: ICT1001 Computer Systems 2009 214 Troubleshooting Motherboards Symptoms Failures fall into three types: catastrophic, component, and ethereal. Catastrophic failure System will not boot. This can occur on rare occasions with a brand-new system due to manufacturing defects, called burn-in failure. ESD shock is the another cause. To fix, replace the motherboard. Unitintro: ICT1001 Computer Systems 2009 215 Symptoms (continued) Component failure happens rarely. Component failure appears as flaky connections between a device and motherboard, or as intermittent problems. Among other things, consider a faulty component, a buggy device driver, buggy application software, a corrupted operating system, overheating, and power supply problems. Unitintro: ICT1001 Computer Systems 2009 216 Symptoms (continued) Ethereal symptoms Things just don’t work all of the time. PC reboots itself for no apparent reason. Blue Screens of Death appear as the computer crashes. Causes include faulty components, buggy device drivers or application software, slight corruption of the operating system, and power supply problems. Unitintro: ICT1001 Computer Systems 2009 217 Techniques Isolate the problem by eliminating potential factors. Check, replace, verify good component. If the hard drive doesn’t work, try a different hard drive or try the same hard drive with a different motherboard. If the new hard drive works, you know it wasn’t the motherboard. If the same hard drive with a different motherboard works, you can suspect theSystems 2009 Unitintro: ICT1001 Computer 218 motherboard. Options There are a couple of options for dealing with a motherboard failure. Catastrophic failure: replace the motherboard. Component failure: consider an add-on card to replace the device. Consider a BIOS update or replace the motherboard if the device issue is a problem other than physical damage Figure 7.48 Adaptec PCIe SATA card Unitintro: ICT1001 Computer Systems 2009 219 Digital Logic Gates IT6001 – Computer Systems LN 4: ICT1001 Computer Systems 220 Overview At the end of this session, you will: Be able to understand what Digital Logic is Learn about Gates – Truth Tables Construct truth tables given boolean expressions Simplify the resulting expression algebraically Represent the expression as a circuit using logic gates LN 4: ICT1001 Computer Systems 221 Digital systems A digital system is a system whose inputs and outputs fall within a discrete, finite set of values Two main types: Combinational Outputs dependent only on current input Sequential Outputs dependent on both past and present inputs LN 4: ICT1001 Computer Systems 222 Combinational logic circuits Aims: To express the inputs and outputs of a system in binary form To develop the relationships between these inputs and outputs as a truth table To simplify the Boolean expression To select suitable electronic devices to implement the required function LN 4: ICT1001 Computer Systems 223 Example Consider a buzzer in your car that sounds when : The lights are on and The door is open and No key is in the ignition If we were to build a digital system, what do you think would be the best way to represent each of these conditions? (Remember: we are looking for a representation) LN 4: ICT1001 Computer Systems 224 Example Consider a buzzer in your car that sounds when : The lights are on and The door is open and No key is in the ignition A P B Buzzer system Activ C e Variab Valu Situati le A e1 Lights onare 0 Lights on are B 1 Door off is 0 Door open is C 1 Key is in closed 0 Key is out of ignition P 1 Buzzer ignitionis 0 Buzzer on is LN 4: ICT1001 Computer Systems off 225 Example A B Truth Table 0 C 0 P A Truth Table can be used 0 0 0 0 1 to show the relationships 0 1 0 0 between : 0 1 0 1 the 3 inputs and 1 0 0 1 0 0 the single output 0 1 1 1 0 0 1 1 1 1 0 lights Implementation as a door buzzer circuit using logic gateskeys LN 4: ICT1001 Computer Systems 226 SUMMARY ⮚ Inputs and Outputs are expressed in Binary Form ⮚ A truth table shows the relationship between inputs and outputs ⮚ A circuit is built based on the above LN 4: ICT1001 Computer Systems 227 Logical operations The three basic logical operations are: AND OR NOT AND is denoted by a dot (·). OR is denoted by a plus (+). NOT is denoted by an overbar ( ¯ ), a single quote mark (') after, or (~) before the variable. LN 4: ICT1001 Computer Systems 228 Notation examples Examples: Y =A ⋅B is read “Y is equal to A AND B.” z =x +y is read “z is equal to x OR y.” = X A is read “X is equal to NOT A.” ▪ Note: The statement: 1 + 1 = 2 (read “one plus one equals two”) is not the same as 1 + 1 = 1 (read “1 or 1 equals 1”). LN 4: ICT1001 Computer Systems 229 Truth tables and logic gates Circuits with one input A A P Buffer P = A P 0 A 0 1 Not P=A P 0 1 1 230 LN 4: ICT1001 Computer Systems And – or gates Circuits with two Inputs A B P 0 0 A P AND 0 B P = A.B 0 1 0 1 0 0 1 1 A B 1 P 0 0 OR P=A+B 0 0 1 1 1 0 1 LN 4: ICT1001 Computer Systems 1 1 231 Nand – nor gates Circuits with two Inputs A B P A P NAND P = A.B 0 0 B 1 0 1 1 1 0 A B1 1 P1 0 00 NOR P=A+B 1 0 1 0 1 0 0 LN 4: ICT1001 Computer Systems 1 1 232 XOR – XNOR GATES Circuits with two Inputs: XOR P=A⊕B A B P 0 0 0 0 1 1 1 0 1 XNOR P = A ⊕ B 1 A 1 B 0 P 0 0 1 0 1 0 1 0 0 LN 4: ICT1001 Computer Systems 1 1233 Activity 1 – logic gate simulator We will now simulate these logic gates using the web-based simulator at http://logic.ly/dem o LN 4: ICT1001 Computer Systems 234 THE NOT SYMBOL You should be aware that not A and not B and not (A and B) equivalent to NAND are different. LN 4: ICT1001 Computer Systems 235 THE NOT SYMBOL – prove it Use the simulator to prove that the statement below is accurate not A and not B and not (A and B) are different. LN 4: ICT1001 Computer Systems 236 Primitive gates All circuits can actually be made using AND, OR and NOT gates if required. In terms of components used, it is generally easier to build inverting functions. They typically require less transistors and also work faster than their non- inverting cousins. LN 4: ICT1001 Computer Systems 237 ACTIVITY 2 A B A+B A.B A.B P Complete the truth table for this circuit and name the 0 0 0 0 1 0 equivalent primitive function/gate. 0 1 1 0 1 1 1 0 1 0 1 1 1 1 1 1 0 0 LN 4: ICT1001 Computer Systems 238 Truth tables Used to evaluate any logic function Consider F(X, Y, Z) = X Y + Y Z X Y Z XY Y YZ F=XY+YZ 0 0 0 0 1 0 0 0 0 1 0 1 1 1 0 1 0 0 0 0 0 0 1 1 0 0 0 0 1 0 0 0 1 0 0 1 0 1 0 1 1 1 1 1 0 1 0 0 1 1 1 1 1 0 0 1 LN 4: ICT1001 Computer Systems 239 Logic diagrams and expressions Truth Logic Equation F =X +Y ⋅Z X Y ZTable 000 0 F =X +Y Z 001 1 010 0 Logic 011 0 X Diagram 100 1 Y F 101 1 110 1 Z 111 1 Boolean equations, truth tables and logic diagrams describe the same function! Truth tables are unique, but expressions and logic diagrams are not. This gives flexibility in implementing functions. 240 LN 4: ICT1001 Computer Systems MINIMIZING COMPLEX boolean expressions Consider my car which complains by sounding a buzzer when I have left the lights on or left the car in gear (not in Park) and taken the keys out of the ignition: A B C P what I’ve done (lights on = 1) (in gear = 1) (keys out = 0) (buzzer) 0 0 0 0 0 0 1 0 0 1 0 1 left in gear 0 1 1 0 1 0 0 1 left lights on 1 0 1 0 1 1 0 1 both 1 1 1 0 A.B.C + A.B.C + A.B.C LN 4: ICT1001 Computer Systems 241 The expression can be simplified A B C P A.C B.C A.C + B.C 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 1 0 1 1 0 1 1 0 0 0 0 1 0 0 1 1 0 1 1 0 1 0 0 0 0 1 1 0 1 1 1 1 1 1 1 0 0 0 0 A.B.C + A.B.C + A.B.C = A.C + B.C = (A + B).C LN 4: ICT1001 Computer Systems 242  A circuits desired outputs can be specified in terms A boolean (logical) expression can be derived from the truth table. The boolean expression can then be simplified Simpler equations lead to simpler implementations now we see how… LN 4: ICT1001 Computer Systems 243 Algebraic laws DeMorgan’s Laws The AND and OR functions can be shown to be related to each other through the following equations: LN 4: ICT1001 Computer Systems 244  Boolean Algebraic Laws ▪ Invented by George Boole in 1854 ▪ An algebraic structure defined by a set B = {0, 1}, together with two binary operators (+ and ·) and a unary operator ( ) 1 X + =X 2 X. =X Identity.3 0.4 element X + =1 X1. =0.5 1 =X.6 X+ X 0. =X Tautology.7 X + =1.8 X. X X =0 Complement.9 X. X X= Involution. X 10 X + =Y + 11 X =Y Commutati.12 Y + XZ X +.13 Y ZX X( Z (XY veAssociativ (X + = +Z =.14 Y) X(Y = X (Y +X ).15 ) Y ) e Distributiv X+ = (X + (X +.16 + Z) Y Z.17 e X + =X. X YZ. =X +Y) Z) DeMorga ’s. Y Y. Y Y n LN 4: ICT1001 Computer Systems 245 Example Simplify the following Expression A.B + A.C+ A.C + A.B distributive A.(B + B) + A.(C + C) re- distribute A.1 + A.1 complementary A+A 246 LN 4: ICT1001 Computer Systems Activity 2 Simplify the following Expression: AB + AC + BC LN 4: ICT1001 Computer Systems 247 Useful theorems Minimization ▪ Minimization XY+XY=Y (dual) Absorption (X+Y)(X+Y) = Y X+XY=X ▪ Absorption (dual) Simplification X · (X + Y) = X X+XY=X+ Y ▪ Simplification (dual) DeMorgan’s X+Y=X·Y X · (X + Y) = X · Y ▪ DeMorgan’s (dual) LN 4: ICT1001 Computer Systems 248 ACTIVITY 3 SIMPLIFY IN ORDER TO CONTAIN THE SMALLEST NUMBER OF LITERALS: A B +A C D +A BD +A C D +A BC D LN 4: ICT1001 Computer Systems 249 SOLUTION A B +A C D +A BD +A C D +A BC D = AB + ABCD + A C D + A C D + A B D = AB + AB(CD) + A C (D + D) + A B D = AB + A C + A B D = B(A + AD) +AC = B (A + D) + A C (has only 5 literals) LN 4: ICT1001 Computer Systems 250 To sum up… Binary variables take on one of two values. Logical operators operate on binary values and binary variables. Basic logical operators are the logic functions AND, OR and NOT. Logic gates implement logic functions. Boolean Algebra: a useful mathematical system for specifying and transforming logic functions. We study Boolean algebra as a foundation for designing and analyzing digital systems! LN 4: ICT1001 Computer Systems 251 TO SUM UP… Express the inputs and outputs of a system in binary form Develop the relationships between these inputs and outputs as a truth table Simplify the Boolean expression (if its needed) Select suitable electronic devices to implement the required function LN 4: ICT1001 Computer Systems 252 Questions for consideration … How can we attain a “simplest” expression? Is there only one minimum cost circuit? LN 4: ICT1001 Computer Systems 253 Storage Technologies Unitintro: ICT1001 Computer Systems 2009 254 Overview In this chapter, you will learn how to: Explain how hard drives work Identify and explain the PATA and SATA hard drive interfaces Describe how to protect data with RAID Describe hard drive installation Unitintro: ICT1001 Computer Systems 2009 255 How Hard Drives Work Hard Disk Drives Basics (Click here) A traditional hard disk drive (HDD) is composed of individual disks or platters. The platters are comprised of aluminum and coated with a magnetic medium. Two tiny read/write heads service each platter. Unitintro: ICT1001 Computer Systems 2009 256 Inside the Hard Drive Figure 9.1 Inside the magnetic hard drive Unitintro: ICT1001 Computer Systems 2009 257 Spindle (or Rotational) Speed Hard drives run at a set spindle speed, measured in revolutions per minute (RPM) Older drives ran at 3600 revolutions per minute (RPM). Common speeds are 5400, 7200, 10,000, and 15,000 RPM. Faster speeds means better performance, but also, possible overheating. Unitintro: ICT1001 Computer Systems 2009 258 Drive Bay Fan Figure 9.3 Bay fan Unitintro: ICT1001 Computer Systems 2009 259 Solid-State Drives A solid-state drive (SSD) are based on semiconductors and transistors with no moving parts. Address shortcomings of HDDs Expensive compared to HDDs Solid-state technology is commonly used in desktop and laptop hard drives, memory cards, cameras, USB thumb drives, etc. Unitintro: ICT1001 Computer Systems 2009 260 Solid-State Drives (continued) SSD form factors are typically 1.8- inch, 2.5-inch, or (rarely) 3.5-inch. Other variations include: mSATA – standard form used in portable devices M.2 Add-on PCIe cards SSDs operate by writing data to high- speed flash memory cells. Unitintro: ICT1001 Computer Systems 2009 261 Hybrid Hard Drives Windows supports hybrid hard drives. Combine flash memory and spinning platters Fast boot times Add 20–30 more minutes of battery life for p