1100-Ch02.docx

The choice of motherboard and external components influences the selection of the case and power supply. The motherboard form factor must be matched with the correct type of computer case and power supply. For example, an ATX motherboard requires both an ATX-compatible case and power supply. You ca...

The choice of motherboard and external components influences the selection of the case and power supply. The motherboard form factor must be matched with the correct type of computer case and power supply. For example, an ATX motherboard requires both an ATX-compatible case and power supply. You can select a larger computer case to accommodate additional components that may be required in the future. Or you might select a smaller case that requires minimal space. In general, the computer case should be durable, easy to service, and have enough room for expansion. Cases often come with a power supply preinstalled. In this situation, you still need to verify that the power supply provides enough power to operate all the components that will be installed in the case. A computer has many internal components that generate heat while the computer is running. Case fans should be installed to move cooler air into the computer case while moving heat out of the case. When choosing case fans, there are several factors to consider as described in the following table. **Note**: The direction of air flow created by all the fans in the case must work together to inject cooler air and expel hotter air. Installing a fan backwards or using fans with the incorrect size or speed for the case can cause the air flows to work against each other. When selecting a PC case fan, there are several important factors to consider to ensure optimal cooling and performance for your system: 1. **Size**: Common sizes include 120mm, 140mm, and 200mm. Ensure the fan size is compatible with your case. 2. **Airflow (CFM)**: Higher airflow fans move more air, which is crucial for cooling. Look for fans with a high CFM (Cubic Feet per Minute) rating. 3. **Noise Level (dBA)**: Consider the noise level, especially if you prefer a quieter setup. Fans with lower dBA ratings are quieter. 4. **Aesthetics**: RGB lighting and fan design can add to the visual appeal of your build. 5. **Budget**: Balance your needs with your budget to find the best value. When selecting a PC power supply unit (PSU), there are several key factors to consider to ensure you get the right one for your needs: - Wattage: Calculate the total power consumption of your system and choose a PSU that provides sufficient wattage with some headroom. This ensures stability and allows for future upgrades - Efficiency: Look for PSUs with high efficiency ratings, such as 80 PLUS Bronze, Silver, Gold, Platinum, or Titanium. Higher efficiency means less wasted energy and lower electricity bills - Form Factor: Ensure the PSU fits your case. Common form factors include ATX, SFX, and TFX. Check your case specifications for compatibility - Modularity: Modular PSUs allow you to connect only the cables you need, reducing clutter and improving airflow. There are fully modular, semi-modular, and non-modular options - Connector Compatibility: Make sure the PSU has all the necessary connectors for your components, such as the motherboard, CPU, GPU, and storage devices - Cooling and Noise: Consider the cooling mechanism and noise level. PSUs with larger, quieter fans or fanless designs can help maintain a silent PC environment. New motherboards often have new features or standards that may be incompatible with older components. When you select a replacement motherboard, make sure that it supports the CPU, RAM, video adapter, and other adapter cards. The socket and chipset on the motherboard must be compatible with the CPU. The motherboard must also accommodate the existing heat sink and fan assembly when reusing the CPU. Pay particular attention to the number and type of expansion slots. Make sure that they match the existing adapter cards and allow for new cards that will be used. The existing power supply must have connections that fit the new motherboard. Finally, the new motherboard must physically fit into the current computer case. - When building a computer, choose a chipset that provides the capabilities that you need. For example, you can purchase a motherboard with a chipset that enables multiple USB ports, eSATA connections, surround sound, and video. - The CPU package must match the CPU socket type. A CPU package contains the CPU, connection points, and materials that surround the CPU and dissipate heat. - Data travels from one part of a computer to another through a collection of wires known as the bus. The bus has two parts. The data portion of the bus, known as the data bus, carries data between the computer components. The address portion, known as the address bus, carries the memory addresses of the locations where data is read or written by the CPU. - The bus size determines how much data can be transmitted at one time. A 32-bit bus transmits 32 bits of data at one time from the processor to RAM, or to other motherboard components, while a 64-bit bus transmits 64 bits of data at one time. The speed at which data travels through the bus is determined by the clock speed, measured in MHz or GHz. - PCI expansion slots connect to a parallel bus, which sends multiple bits over multiple wires simultaneously. PCI expansion slots are being replaced with PCIe expansion slots that connect to a serial bus, which sends one bit at a time at a much faster rate. - When building a computer, choose a motherboard that has slots to meet your current and future needs. Before you buy a CPU, make sure that it is compatible with the existing motherboard. Manufacturers' websites are a good resource to investigate the compatibility between CPUs and other devices.  The speed of a modern processor is measured in GHz. A maximum speed rating refers to the maximum speed at which a processor can function without errors. Two primary factors can limit the speed of a processor: - **Transmission Delay** - The processor chip is a collection of transistors interconnected by wires. Transmitting data through the transistors and wires creates delays. - **Heat Generation** - As the transistors change state from on to off or off to on, a small amount of heat is generated. The amount of heat generated increases as the speed of the processor increases. When the processor becomes too hot, it begins to produce errors. The front-side bus (FSB) is the path between the CPU and the Northbridge. It is used to connect various components, such as the chipset, expansion cards, and RAM. Data can travel in both directions across the FSB. The frequency of the bus is measured in MHz. The frequency at which a CPU operates is determined by applying a clock multiplier to the FSB speed. For example, a processor running at 3200 MHz might be using a 400 MHz FSB. 3200 MHz divided by 400 MHz is 8, so the CPU is eight times faster than the FSB. Processors are further classified as 32-bit and 64-bit. The primary difference is the number of instructions that can be handled by the processor at one time. A 64-bit processor processes more instructions per clock cycle than a 32-bit processor. A 64-bit processor can also support more memory. To utilize the 64-bit processor capabilities, ensure that the operating system and applications installed support a 64-bit processor. The CPU is one of the most expensive and sensitive components in the computer case. The CPU can become very hot; therefore most CPUs require an air-cooled or liquid cooled heat sink, combined with a fan for cooling. New RAM may be needed when an application locks up or the computer displays frequent error messages. When selecting new RAM, you must ensure that it is compatible with the current motherboard. Memory modules are commonly purchased in matched capacity pairs to support dual channel RAM that can be accessed at the same time. Also, the speed of the new RAM must be supported by the chipset. It may be helpful to take written notes about the original memory module when you shop for the replacement RAM. Memory may also be categorized as unbuffered or buffered: - **Unbuffered memory** -- This is regular memory for computers. The computer reads data directly from the memory banks making it faster than buffered memory. However, there is a limit on the amount of RAM that can be installed. - **Buffered memory** -- This is specialized memory for servers and high-end workstations that use a large amount of RAM. These memory chips have a control chip built into the module. The control chip assists the memory controller in managing large quantities of RAM. Avoid buffered RAM for a gaming computer and the average workstation because the extra controller chip reduces RAM speed. You may need to replace an internal storage device when it no longer meets your customer's needs, or it fails. Signs that an internal storage device is failing might be unusual noises, unusual vibrations, error messages, or even corrupt data or applications that do not load. - Factors to consider when purchasing a new hard disk drive are listed in the figure. - Internal drives usually connect to the motherboard with SATA while external drives connect with USB, eSATA, or Thunderbolt. Legacy motherboards may only offer the IDE or EIDE interface. When selecting a HDD, it is important to choose one that is compatible with the interfaces offered by the motherboard. - Most internal HDDs are available in the 3.5 inch (8.9 cm) form factor, however 2.5 inch (6.4 cm) drives are becoming popular. SSDs are generally available in the 2.5 inch (6.4 cm) form factor. - Note: SATA and eSATA cables are similar but they are not interchangeable. Many of the functions of the hardware of a computer are found onboard the motherboard, such as audio, USB, or network connection. Adapter cards, also called expansion cards or add-on cards, are designed for a specific task and add extra functionality to a computer. They can also be installed when an onboard function has failed. There are a variety of adapter cards available that are used to expand and customize the capability of a computer. The following list provides an overview of expansion cards that may be upgraded: - **Graphics card** - The type of graphics card installed affects the overall performance of a computer. For example, a graphics card that needs to support intensive graphics could be RAM intensive, CPU intensive, or both. The computer must have the slots, RAM, and CPU to support the full functionality of an upgraded graphics card. Choose the graphics card based on current and future needs. For example, to play 3D games, the graphics card must meet or exceed the minimum requirements. Some GPUs are integrated into the CPU. When the GPU is integrated into the CPU, there is no need to purchase a graphics card unless advanced video features, such as 3D graphics, or very high resolution are required. - **Sound card** - The type of sound card installed determines the sound quality of your computer. A computer system must have quality speakers and a subwoofer to support the full functionality of an upgraded sound card. Choose the correct sound card based on your customer's current and future needs. For example, if a customer wants to hear a specific type of surround sound, the sound card must have the correct hardware decoder to reproduce it. In addition, the customer can get improved sound accuracy with a sound card that has a higher sample rate. - **Storage controller** - Storage controllers can be integrated or added as an expansion card. They allow for the expansion of internal and external drives for a computer system. Storage controllers, such as RAID controllers, can also provide fault tolerance or increased speed. The amount of data and the level of data protection needed for the customer influences the type of storage controller required. Choose the correct storage controller based on your customer's current and future needs. For example, if a customer wants to implement RAID 5, a RAID storage controller with at least three drives is needed. - **I/O card** - Installing an I/O card in a computer is a fast and easy way to add I/O ports. USB are some of the most common ports to install on a computer. Choose the correct I/O card based on your customer's current and future needs. For example, if a customer wants to add an internal card reader, and the motherboard has no internal USB connection, a USB I/O card with an internal USB connection is needed. - **NIC** - Customers often upgrade a network interface card (NIC) to get wireless connectivity or to increase bandwidth. - **Capture card** - A capture card imports video into a computer and records it on a hard drive. The addition of a capture card with a television tuner allows you to view and record television programming. The computer system must have enough CPU power, adequate RAM, and a high-speed storage system to support the capture, recording, and editing demands of the customer. Choose the correct capture card based on your customer's current and future needs. For example, if a customer wants to record one program while watching another, either multiple capture cards or a capture card with multiple TV tuners must be installed. Adapter cards are inserted into two types of expansion slots on a motherboard: - **Peripheral Component Interconnect (PCI)** -- PCI is commonly available to support older expansion cards. - **PCI Express (PCIe)** -- PCIe has four types of slots; x1, x4, x8, and x16. These PCIe slots vary in length from shortest (X1) to longest (x16) respectively. **Note**: If the motherboard does not have a compatible expansion slot, an external device may be an option. Many digital devices such as cameras, smart phones, and tablets use media cards to store information, music, pictures, videos, data, and more. Several media card formats have been developed over the years including: - **Secure digital (SD)** - SD cards were designed for use in portable devices such as cameras, MP3 players, and laptops. SD cards can hold as much as 2 TB of data. - **MicroSD** -- This is a much smaller version of SD, commonly used in smartphones and tablets. - **MiniSD** -- A version of SD between the size of an SD card and a microSD card. The format was developed for mobile phones. - **CompactFlash** - CompactFlash is an older format, but still in wide use because of its high speed and high capacity (up to 128 GB is common). CompactFlash is often used as storage for video cameras. - **Memory** **Stick** -- Created by Sony Corporation, Memory Stick is a proprietary flash memory used in cameras, MP3 players, hand-held video game systems, mobile phones, cameras, and other portable electronics. - **xD** -- Also known as Picture Card, it was used in some digital cameras. External storage offers portability and convenience when working with multiple computers. External USB flash drives, sometimes called thumb drives, are commonly used as removable external storage. External storage devices connect to an external port using USB, eSATA, or Thunderbolt ports. Choose the correct type of external storage for your customer's needs. For example, if your customer needs to transfer a small amount of data, such as a single presentation, an external flash drive is a good choice. If your customer needs to back up or transfer large amounts of data, choose an external hard drive. System panel connectors include: - **Power Button** - The power button turns the computer on or off. If the power button fails to turn off the computer, hold down the power button for several (i.e., 5 or more) seconds. - **Reset Button** - The reset button (if available) restarts the computer without turning it off. - **Power LED** - The power LED remains lit when the computer is on, and often blinks when the computer is in sleep mode. - **Drive Activity LEDs** - The drive activity LED remains lit or blinks when the system is reading or writing to hard drives. - **System Speaker** - The motherboard uses a case speaker (if available) to indicate the computer's status. For example, one beep indicates that the computer started without problems. If there is a hardware problem, a series of diagnostic beeps is issued to indicate the type of problem. It is important to note that the system speaker is not the same as the speakers the computer uses to play music and other audio. The system speaker cable typically uses four pins on the system panel connector. - **Audio** - Some cases have audio ports and jacks on the outside to connect microphones, external audio equipment such as signal processors, mixing boards, and instruments. Special audio panels can also be purchased and connected directly to the motherboard. These panels can install into one or more external drive bays, or be standalone panels. System panel connectors are not keyed. However, each front panel cable usually has a small arrow indicating pin 1, and each pair of LED pins on the motherboard system panel connector has pin 1 marked with a plus sign (+). New cases and motherboards have USB 3.0 or may even have USB 3.1 capabilities. The USB 3.0 and 3.1 motherboard connector is similar in design to a USB connector, but has additional pins. USB connector cables are often 9 or 10 pins arranged in two rows. These cables connect to USB motherboard connectors. Arrangements may allow for two USB connections, so USB connectors are often in pairs. Sometimes the two connectors are together in one piece, and can be connected to the entire USB motherboard connector. USB connectors can also have four or five pins or individual groups of four or five pins. Most USB devices only require the connection of four pins. The fifth pin is used to ground the shielding of some USB cables. **CAUTION**: Make sure that the motherboard connector is marked USB. FireWire connectors are very similar. Connecting a USB cable to a FireWire connector will cause damage. Generally, if a button or LED does not function, the connector is incorrectly oriented. To correct this, shut down the computer and unplug it, open the case, and turn the connector around for the button or LED that does not function. To avoid wiring incorrectly, some manufacturers include a keyed pin extender that combines multiple front-panel cables (i.e., power and reset LEDs) connectors into one connector. **Installation Tip**: The panel connector and case cable ends are very small. Take pictures of them to locate pin 1. Because space in the case can be limited at the end of assembly, a part retriever can be used to plug the cables into the connectors. In this chapter you learned that assembling computers is often a large part of a technician's job and that as a technician, you must work in a logical, methodical manner when working with computer components. For example, the choice of motherboard and external components influences the selection of the case and power supply and the motherboard form factor must be matched with the correct type of computer case and power supply. You learned that PC power supplies convert AC input to DC output voltages. Power supplies typically provide voltages of 3.3V, 5V, and 12V to power the various internal components of the computer and that the power supply must have the proper connectors for the motherboard and the various types of devices to be powered. After learning about power supplies, you installed a power supply as well as other internal components including a CPU and RAM. You learned that when you select a motherboard it must support the CPU, RAM, video adapter, and other adapter cards and that the socket and chipset on the motherboard must be compatible with the CPU. The motherboard sockets may be designed to support Intel CPUs, which support an LGA architecture, or AMD CPUs which support a PGA architecture. In addition to learning about CPU architectures, you also learned that when selecting new RAM, it must be compatible with the motherboard and that the speed of the RAM must be supported by the chipset. You then performed labs where you installed a CPU, a heat sink/fan assembly, and RAM modules on the motherboard. You also installed the motherboard assembly into the computer case. Next, you learned about the various types of storage drives, such as internal drives, external drives, hard-disk drives, solid-state drives, and optical drives and the factors to consider when selecting the appropriate drive. You then installed drives in the computer case. Finally, you learned about adapter cards, which are also called expansion cards, or add-on cards. There are many types of adapter cards and each is designed for a specific task and to add extra functionality to a computer. The chapter covered graphics cards, sound cards, storage controllers, I/O cards, and NICs. These adapter cards are inserted into two types of expansion slots on a motherboard: PCI and PCIe. At the end of the chapter, there were labs where you installed an adapter card, connected the appropriate internal power cables, front panel connectors, and performed final computer assembly.