ITCNA_Chapter 2_Installing System Devicesv1.pdf

ITCNA1-12 Chapter 2 Installing system devices Installing System Devices: Objectives Install and configure power supplies and cooling Select and install storage devices Install and configure system memory Install and configure CPUs Install and configure power supplies and cooling: Underst...

ITCNA1-12 Chapter 2 Installing system devices Installing System Devices: Objectives Install and configure power supplies and cooling Select and install storage devices Install and configure system memory Install and configure CPUs Install and configure power supplies and cooling: Understanding the power requirements of all the components and the maximum power output is crucial in managing new builds, upgrades, and repairs. Along with power, all PC components generate heat. Managing heat by installing and maintaining cooling systems makes for a more reliable computing environment. A computer that runs too hot risks damaging its own components and is likely to run at reduced performance levels. Install and configure power supplies and cooling: Power Supply Units The power supply unit (PSU) delivers direct current (DC) low voltage power to the PC components. A PSU contains a rectifier to convert alternating current (AC ) building power to DC voltage output, transformers to step down to lower voltages, and filters and regulators to ensure consistent output voltage levels. The other important component in the PSU is the fan, which dissipates the heat generated. The power supply’s size and shape determine its compatibility with the system case, in terms of available room plus screw and fan locations. The form factor also determines compatibility with the motherboard, in terms of power connectors. Most PSUs designed for use with desktop PCs are based on the ATX form factor. Install and configure power supplies and cooling: Power Supply Units A PSU is plugged into an electrical outlet using a suitable power cord. Before doing this, you must ensure that the PSU is compatible with the input voltage from the outlet. A PSU designed only for use in North America, where the input voltage for most homes and offices is 120 VAC (low-line), will not work in the UK, where the voltage is 230 VAC (high-line). Also, facilities such as data centers typically use high-line voltage because it is more efficient. Most PSUs are dual voltage and are auto-switching; some have a manual switch to select the correct voltage; fixed voltage types can only accept either low-line or high-line. The input operating voltages should be clearly marked on the unit and accompanying documentation. Install and configure power supplies and cooling: Wattage Rating Power is the rate at which things generate or use energy. Power is measured in watts (W), calculated for electrical components as voltage multiplied by current (V*I). A PSU must be able to meet the combined power requirements of the PC’s components. The PSU’s output capability is measured as its wattage rating. A PSU designed for use in a standard desktop PC is typically rated at around 200–300 W. Enterprise workstation PCs and servers often have units rated over 300 W to meet the demands of multiple CPUs, additional memory modules, disk drives, and tape units. Gaming PCs might require 500 W or better power supplies to cope with the high specification CPU and graphics card(s). Install and configure power supplies and cooling: Power Supply Connectors Each PSU has a number of power connectors attached. The power connectors supply DC voltage to the motherboard and devices at 3.3 VDC, 5 VDC, and 12 VDC. Not all components use power at precisely these voltages. Voltage regulators are used to correct the voltage supplied from the PSU to the voltage required by the component. The motherboard’s power port is referred to as the P1 connector. A PSU will also have a number of Molex and/or SATA device power connectors and 4/6/8-pin connectors for use with CPU and PCIe adapter card power ports. Install and configure power supplies and cooling: Power Supply Connectors 20-pin to 24-pin Motherboard Adapter The ATX PSU standard has gone through several revisions, specifying different connector form factors. In the original ATX specification, the P1 connector is 20-pin (2x10). Wires with black insulation are ground, yellow are +12 V, red are +5 V, and orange are +3.3 V. Modular Power Supplies A modular PSU has power connector cables that are detachable from the unit. Reducing the number of cables to the minimum required minimizes clutter within the chassis, improving air flow and cooling. Install and configure power supplies and cooling: Power Supply Connectors Redundant Power Supplies A computer system may be fitted with two PSUs, with one acting as a failover redundant power supply. This could also be connected to a different grid power circuit. A redundant PSU configuration requires a compatible motherboard. This configuration is more commonly found on server systems than on desktop PCs. On a server, typically each PSU plugs into a backplane and is hot- swappable. This allows a faulty unit to be removed and replaced without having to open the case and without the server ever losing power. Install and configure power supplies and cooling: Fan Cooling Systems Components in a computer system emit heat because of some degree of resistance when electrical current passes through them. Without a cooling solution, this heat will raise the temperature of each component and increase the ambient temperature inside the case. Excessive temperatures can cause the components to malfunction or even damage them. This issue particularly affects CPUs. While Intel and AMD are both focusing on making new CPU designs more thermally efficient, all CPUs require cooling to keep the temperature within an acceptable operational range. Install and configure power supplies and cooling: Fan Cooling Systems Heat Sinks and Thermal Paste A heat sink is a block of copper or aluminium with fins. The fins expose a larger surface area to the air around the component to achieve a cooling effect by convection. The heat sink is “glued” to the surface of the chip using thermal paste to ensure the best transfer of heat by eliminating small air gaps. A thermal pad performs a similar function. The pad is a compound that is solid at room temperature but softens when heated. This can be easier to apply but does not always perform as reliably. Install and configure power supplies and cooling: Fan Cooling Systems Fans A heat sink is a passive cooling device. Passive cooling means that it does not require extra energy (electricity) to work. To work well, a heat sink requires good airflow around the PC. It is important to try to keep “cable clutter” to a minimum and to ensure that spare adapter slots are covered by blanking plates. Many PCs have components that generate more heat than can be removed by passive cooling. A fan improves airflow, which helps to dissipate heat. Fans are used for the power supply and chassis exhaust points. The fan system will be designed to draw cool air from the low vents in the front of the case over the motherboard and expel warmed air from the fan positioned at the top of the back of the case. Most heat sinks are fitted with fans to improve their cooling performance. The fan’s power connector must be plugged into a motherboard fan power port. Install and configure power supplies and cooling: Fan Cooling Systems Fans Thermometer sensors are used at each fan location to set an appropriate speed and to detect whether a fan has failed. Some chassis designs incorporate a plastic shroud or system of baffles to cover the CPU and channel the flow of air. The shroud is usually attached to the case using plastic clips. Both fans and heat sinks become less effective if dust is allowed to build up. These components and any air vents should be cleaned periodically, either manually with a soft brush and/or compressed air or using a vacuum cleaner approved for use with PCs. Install and configure power supplies and cooling: Liquid Cooling Systems PCs used for high-end gaming may generate more heat than basic thermal management can cope with. PCs used where the ambient temperature is very high may also require exceptional cooling measures. A liquid-based cooling system refers to a system of pumping water around the chassis. Water is a more effective coolant than air convection, and a good pump can run more quietly than numerous fans. An open-loop, liquid-based cooling system uses the following components: The water loop/tubing and pump push the coolant added via the reservoir around the system. Water blocks and brackets are attached to each device to remove heat by convection. These are attached in a similar way to heat sink/fan assemblies and then connected to the water loop. Radiators and fans are positioned at air vents to dispel the excess heat. Install and configure power supplies and cooling: Liquid Cooling Systems An open-loop system will usually need draining, cleaning, and refilling periodically. It is also important to keep the fans and radiators dust-free. The system should also be drained prior to moving the PC to a different location. Select and install storage devices Mass Storage Devices Non-volatile storage devices hold data when the system is powered off. These devices are also referred to as mass storage. Mass storage devices use magnetic, optical, or solid-state technology to store data. A mass storage device installed as an internal component is referred to as a fixed disk. Storage devices are produced in a number of standard widths: 5.25 inches, 3.5 inches, and 2.5 inches. The computer chassis has several drive bays to fit these form factors. Form factor bays with a 5.25-inch width are provided with removable panels so that they can be used with devices that have removable media, such as DVD drives and smart card readers. Select and install storage devices Mass Storage Devices A fixed disk is typically installed to a drive bay using a caddy. You screw the drive into the caddy, then screw the caddy into the drive bay. A caddy can also allow you to fit a drive of a different size to the bay. Some caddies use rails so that you can pull the drive out without having to open the case. Select and install storage devices Mass Storage Devices Apart from cost, several factors impact the choice of mass storage device: Reliability This concerns both the risk of total device failure and the risk of partial data corruption. Reliability and expected lifespan are rated by various statistics that are different for each technology type. Performance When comparing different types of storage technology, you need to evaluate performance for the type of data transfer that the device will use predominantly. For example, read and write performance have different characteristics. There are also differences between sequential access (reading data from the same “block” as might happen when transferring a large file) and random access (reading data from different locations on the drive or transferring lots of small files). Along with the data throughput measured in MB/s or GB/s, you may need to consider the number of input/output operations per second (IOPS) that can be achieved by a device for different kinds of data transfer operations. Select and install storage devices Mass Storage Devices Apart from cost, several factors impact the choice of mass storage device: Use Reliability and performance factors can only be properly evaluated when considering use. Examples of how storage is used include running an OS, hosting a database application, streaming audio/video data, as removable media, and for data backup and archiving. These use cases have different cost, reliability, and performance considerations. Select and install storage devices Solid-State Drives A solid-state drive (SSD) uses flash memory technology to implement persistent mass storage. Flash memory performs much better than the mechanical components used in hard disk drives, especially in terms of read performance. Risks from total failure of the device due to mechanical shock and wear are generally lower. Costs per gigabyte have fallen rapidly in the last few years. Flash chips are also susceptible to a type of degradation over the course of many write operations. The drive firmware and operating system use wear levelling routines that evenly distribute writing on all blocks of an SSD to optimize the life of the device. Select and install storage devices Hard Disk Drives A hard disk drive (HDD) stores data on metal or glass platters that are coated with a magnetic substance. The top and bottom of each platter is accessed by its own read/write head, moved by an actuator mechanism. The platters are mounted on a spindle and spun at high speed. Each side of each platter is divided into circular tracks, and a track contains several sectors, each with a capacity of 512 bytes. This low-level formatting is also referred to as the drive geometry. HDDs are now most typically installed as a second drive/RAID array for data storage, but students might still come across legacy systems using HDDs as the main drive. Select and install storage devices Hard Disk Drives Select and install storage devices Redundant Array of Independent Disks Whether it is the system files required to run the OS or data files generated by users, an HDD or SSD stores critical data. If a boot drive fails, the system will crash. If a data drive fails, users will lose access to files and there may be permanent data loss if those files have not been backed up. To mitigate these risks, the disks that underpin the mass storage system can be provisioned as a redundant array of independent disks (RAID). Redundancy sacrifices some disk capacity but provides fault tolerance. To the OS, the RAID array appears as a single storage resource, or volume, and can be partitioned and formatted like any other drive. Select and install storage devices Redundant Array of Independent Disks A RAID level represents a drive configuration with a given type of fault tolerance. Basic RAID levels are numbered from 0 to 6. There are also nested RAID solutions, such as RAID 10 (RAID 1 + RAID 0). RAID can be implemented using features of the operating system, referred to as software RAID. Hardware RAID uses a dedicated controller, installed as an adapter card. The RAID disks are connected to SATA ports on the RAID controller adapter card, rather than to the motherboard. Select and install storage devices Redundant Array of Independent Disks Hardware solutions are principally differentiated by their support for a range of RAID levels. Entry-level controllers might support only RAID 0 or RAID 1, whereas mid-level controllers might add support for RAID 5 and RAID 10. In addition, hardware RAID is often able to hot swap a damaged disk. Hot swap means that the failed device can be replaced without shutting down the operating system. Watch the following video: https://youtu.be/eE7Bfw9lFfs and critically discuss the differences between each implementation as it is crucial for you to understand each. Select and install storage devices Removable Storage Drives Removable storage can refer either to a storage device that can be moved from computer to computer without having to open the case or to storage media that is removable from its drive. Drive Enclosures HDDs and SSDs can be provisioned as removable storage in an enclosure. The enclosure provides a data interface (USB, Thunderbolt, or eSATA), a power connector (if necessary), and protection for the disk. Select and install storage devices Removable Storage Drives Flash Drives and Memory Cards The flash memory underpinning SSDs can also be provisioned in the flash drive and memory card form factors. A flash drive—also called a USB drive, thumb drive, or pen drive— is simply a flash memory board with a USB connector and protective cover. This type of drive plugs into any spare USB port. The memory card form factor is used in consumer digital imaging products, such as digital still and video cameras, and to expand smartphone and tablet storage. A PC can be fitted with a memory card reader device. These are usually designed to fit in a front-facing drive bay. The reader then needs to be connected to a USB controller. Select and install storage devices Optical Drives Compact Discs (CDs), Digital Versatile Discs (DVDs), and Blu-ray Discs (BDs) are mainstream storage formats for music and video retail. All types of optical media use a laser to read the data encoded on the disc surface. The discs are marketed as being hard-wearing, but scratches can render them unreadable. Optical drives are rated according to their data transfer speed. An optical drive that can perform recording/rewriting is marketed with three speeds, always expressed as the record/rewrite/read speed (for example, 24x/16x/52x). New drives are generally multi-format, but you may come across older drives with no Blu-ray support. Install and configure system memory: System RAM and Virtual Memory The CPU works by processing the instructions generated by software (processes) in a pipeline. Instructions that are at the top of the pipeline are stored in the CPU’s registers and cache. The CPU only has a small amount of cache, however. Consequently, the operation of the CPU must be supported by additional storage technologies. When a process is executed or a data file opened, the image is loaded from the fixed disk into system memory. Instructions are fetched from system memory and into the CPU’s cache and registers as required. This process is handled by a memory controller. System memory is implemented as random-access memory (RAM) devices. RAM is faster than the flash memory used for SSDs and much faster than an HDD, but it is volatile. Volatile means that the memory device can only store data when it is powered on. System memory is measure in gigabytes (GB). The amount of system RAM determines the PC’s ability to work with multiple applications at the same time and to process large files efficiently. Install and configure system memory: System RAM and Virtual Memory Virtual RAM/Virtual Memory If there is not enough system RAM, the memory space can be extended by using disk storage. This is referred to as a pagefile or swap space. The total amount of addressable memory (system RAM plus swap space) is referred to as virtual memory or virtual RAM. With virtual memory, the OS assigns memory locations to processes in 4 kilobyte chunks called pages. The memory controller moves inactive pages of memory to the swap space to free up physical RAM and retrieves pages from the swap space to physical RAM when required by process execution. An excessive amount of such paging activity will slow the computer down because disk transfer rates are slower than RAM transfer rates. Install and configure system memory: System RAM and Virtual Memory Address Space The bus between the CPU, memory controller, and memory devices consists of a data pathway and an address pathway: The width of the data pathway determines how much information can be transferred per clock cycle. In a single channel memory controller configuration, the data bus is usually 64 bits wide. The width of the address bus determines how many memory locations the CPU can keep track of and consequently limits to the maximum possible amount of physical and virtual memory. A 32-bit CPU with a 32-bit address bus can access a 4 GB address space. In theory, a 64-bit CPU could implement a 64-bit address space (16 exabytes), but most 64-bit CPUs actually use a 48-bit address bus, allowing up to 256 terabytes of memory. Install and configure system memory: RAM Types Modern system RAM is implemented as a type called Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM). Dynamic RAM stores each data bit as an electrical charge within a single bit cell. A bit cell consists of a capacitor to hold a charge (the cell represents 1 if there is a charge and 0 if there is not) and a transistor to read the contents of the capacitor. Synchronous DRAM (SDRAM) is so-called because its speed is synchronized to the motherboard system clock. Double Data Rate SDRAM (DDR SDRAM) makes two data transfers per clock cycle. Subsequent generations of DDR technology—DDR2, DDR3, DDR4, and DDR5— increase bandwidth by multiplying the bus speed, as opposed to the speed at which the actual memory devices work. This produces scalable speed improvements without making the memory modules too unreliable or too hot. Design improvements also increase the maximum possible capacity of each memory module. Install and configure system memory: Memory Modules A memory module is a printed circuit board that holds a group of RAM devices that act as a single unit. Memory modules are produced in different capacities. Each DDR generation sets an upper limit on the maximum possible capacity. DDR for desktop system memory is packaged in a form factor called dual inline memory module (DIMM). The notches (keys) on the module’s edge connector identify the DDR generation (DDR3/DDR4/DDR5) and prevent it from being inserted into an incompatible slot or inserted the wrong way around. DDR DIMMs typically feature heat sinks, due to the use of high clock speeds. The DIMM’s DDR type must match the motherboard. Laptop RAM is packaged in a smaller form factor called Small Outline DIMM (SODIMM). Install and configure system memory: Multi-channel System Memory In the 2000s, the increasing speed and architectural improvements of CPU technologies led to memory becoming a bottleneck to system performance. To address this, Intel and AMD developed a dual-channel architecture for DDR memory controllers. Dual-channel was originally used primarily on server-level hardware but is now a common feature of desktop systems and laptops. Single-channel memory means that there is one 64-bit data bus between the CPU, memory controller, and RAM devices. With a dual-channel memory controller, there are effectively two 64- bit pathways through the bus to the CPU, meaning that 128 bits of data can be sent per transfer rather than 64 bits. This feature requires support from the CPU, memory controller, and motherboard but not from the RAM devices. Ordinary RAM modules are used. There are no “dual-channel” DDR memory modules. Install and configure system memory: ECC RAM Error correcting code (ECC) RAM is used for workstations and servers that require a high level of reliability. For each transfer, ECC RAM performs a hash calculation on the data value and stores it as an 8-bit checksum. This checksum requires an extra processor chip on the module and a 72-bit data bus rather than the regular 64 bits. The memory controller performs the same calculation and should derive the same checksum. This system can detect and correct single-bit errors and allow the PC to continue functioning normally. ECC can also detect errors of 2, 3, or 4 bits but cannot correct them. Instead, it will generate an error message and halt the system. Most types of ECC are supplied as registered DIMMs (RDIMMs). A registered DIMM uses an extra component to reduce electrical load on the memory controller. This has a slight performance penalty, but makes the system more reliable, especially if large amounts of memory are installed. Most types of non-ECC memory are unbuffered DIMMs (UDIMMs). Some types of ECC RAM are packaged in UDIMMs, though this is rarer. Install and configure system memory: ECC RAM All these factors must be considered when selecting memory for a system: Both the motherboard and CPU must support ECC operation for it to be enabled. Most motherboards support either UDIMMs or RDIMMs, but not both. If a motherboard does support both, UDIMM and RDIMM modules cannot be mixed on the same motherboard. The system will not boot if there are different types. Mixing non-ECC UDIMMs and ECC UDIMMs is unlikely to work. Install and configure CPUs: CPU Architecture The central processing unit (CPU), or simply the processor, executes program instruction code. When a software program runs (whether it be system firmware, an operating system, anti-virus utility, or word-processing application), it is assembled into instructions utilizing the fundamental instruction set of the CPU platform and loaded into system memory. Install and configure CPUs: CPU Architecture The CPU then performs the following basic operations on each instruction: 1. The control unit fetches the next instruction in sequence from system memory to the pipeline. 2. The control unit decodes each instruction in turn and either executes it itself or passes it to the arithmetic logic unit (ALU) or floating-point unit (FPU) for execution. 3. The result of the executed instruction is written back to a register, to cache, or to system memory. A register is a temporary storage area available to the different units within the CPU working at the same clock speed as the CPU. Cache is a small block of memory that works at the speed of the CPU or close to it, depending on the cache level. Cache enhances performance by storing instructions and data that the CPU is using regularly. Install and configure CPUs: CPU Features Given the architectural features just discussed, the speed at which the CPU runs is generally seen as a key indicator of performance. This is certainly true when comparing CPUs with the same architecture but is not necessarily the case otherwise. Thermal and power performance impose limits to running the CPU faster and faster. Another way to make execution more efficient is to improve the operation of the instruction pipeline. The basic approach is to do the most amount of work possible in a single clock cycle. This can be achieved through simultaneous multithreading (SMT), referred to as HyperThreading by Intel. A thread is a stream of instructions generated by a software application. Most applications run a single process in a single thread; software that runs multiple parallel threads within a process is said to be multithreaded. SMT allows the threads to run through the CPU at the same time. This reduces the amount of “idle time” the CPU spends waiting for new instructions to process. To the OS, it seems as though there are two or more CPUs installed. Install and configure CPUs: CPU Features Another approach is to use two or more physical CPUs, referred to as symmetric multiprocessing (SMP). An SMP-aware OS can then make efficient use of the processing resources available to run application processes on whichever CPU is “available.” This approach is not dependent on software applications being multithreaded to deliver performance benefits. However, a multi-socket motherboard is significantly more costly and so is implemented more often on servers and high-end workstations than on desktops. The CPUs used in each socket must be identical models and specifications and must be models that support SMP. Install and configure CPUs: CPU Features Improvements in CPU fabrication techniques led to the ability to expand compute resources by fabricating multiple CPU cores on a single package. A single-core CPU has a single execution unit and set of registers implemented on a single package. A dual-core CPU is essentially two processors combined in the same package. This means that there are two execution units and sets of registers. Each core will also have its own cache plus access to a shared cache. This is referred to as chip level multiprocessing (CMP). Install and configure CPUs: CPU Features The market has quickly moved beyond dual-core CPUs to multicore packages with eight or more processors. Multicore and multithreading features are designated by nC/nT notation. For example, an 8C/16T CPU with multithreading support has eight cores but processes double that number of simultaneous threads. Install and configure CPUs: CPU Features Finally, a computer can be made more efficient and useful by configuring it to run multiple operating systems at the same time. This is achieved through virtualization software. Each OS is referred to as a virtual machine (VM). Intel’s Virtualization Technology (VT) and AMD’s AMD-V provide processor extensions to support virtualization, also referred to as hardware-assisted virtualization. This makes the VMs run much more quickly. These extensions are usually features of premium models in each processor range. Install and configure CPUs: CPU Socket Types CPU packaging refers to the CPU’s form factor and how it is connected to the motherboard. Intel and AMD use different socket types, so you will not be able to install an AMD CPU in a motherboard designed for an Intel CPU (and vice versa). All CPU sockets use a zero-insertion force (ZIF) mechanism. This means that no pressure is required to insert the CPU, reducing the risk of bending or breaking the fragile pin contacts. Install and configure CPUs: CPU Types and Motherboard Compatibility The nature of the current CPU market means that there is rapid turnover of models. Each vendor releases a CPU design with a number of architectural improvements and quite often with a new socket design. This is referred to as a CPU’s generation. In each generation, the manufacturer releases several models. Motherboards are specific to either Intel or AMD CPUs. Typically, motherboard compatibility is limited to the same generation of CPUs. The CPU must be supported by both the physical form factor of the motherboard’s CPU socket and by the motherboard’s chipset. There are limited opportunities to upgrade the CPU model while keeping the same motherboard, and such upgrades rarely offer much value. Within each generation, CPU brands and models target different market segments, such as desktop, server, and mobile. Install and configure CPUs: CPU Types and Motherboard Compatibility Desktops Desktop is shorthand for a basic PC as used at home or in the office. The term desktop derives from a time when computer cases were designed to sit horizontally on a desk, rather than the vertical tower or all-in-one configurations used today. The desktop segment covers a wide range of performance levels, from budget to gaming PC. Workstations The term workstation can be used in the same way as desktop to refer to any type of business PC or network client. However, in the context of PC sales, most vendors use the term workstation to mean a high-performance PC, such as one used for software development or graphics/video editing. Workstation-class PCs often use similar components to server-class computers. Install and configure CPUs: CPU Types and Motherboard Compatibility Servers Server-class computers must manage more demanding workloads than most types of desktops and operate to greater reliability standards. Server motherboards are often multi-socket, meaning that multiple CPU packages can be installed. Each of these CPUs will have multiple cores and support for multithreading, giving the server the raw processing power it needs to service requests from hundreds or thousands of client systems. Install and configure CPUs: CPU Types and Motherboard Compatibility Mobiles Smartphones, tablets, and laptops need to prioritize power and thermal efficiency plus weight over pure performance. Many mobiles use ARM-based CPUs for this reason, and both Intel and AMD have separate mobile CPU models within each generation of their platforms. Mobile CPUs tend to use different socket form factors to desktops. Many are soldered to the motherboard and not replaceable or upgradeable. End of Chapter 2. Lecturer to complete group discussions in relation to the objectives of this chapter.