System Components

​Central Processing Unit (CPU)

The Central Processing Unit (CPU) is the device that "runs" software programs. Software is composed of many simple instructions. The CPU processes these instructions and directs other components to perform actions, such as displaying an image on the screen or printing a document.

​Memory (System RAM)

When a program is started, its instructions are loaded into system memory. System memory uses a type of technology called Random Access Memory (RAM). Having more RAM allows the PC to open more programs simultaneously to multitask and work on large files more efficiently. As well as system memory size, the speed of the memory subsystem is also important.

​Memory (System RAM)

The CPU fetches instructions from system memory as it needs them. This means that the bus between the CPU and memory, often referred to as the Front Side Bus (FSB), must be as fast as possible. If the memory is slow and the CPU is fast, the CPU will not be supplied with enough instructions and become under-utilized.

​Fixed Disk

Because RAM only works while the power is on, when the computer is turned off, programs and data are stored on a Hard Disk Drive (HDD) or Solid State Drive (SSD). The type and specification of the mass storage drive such as an HDD or SSD is important for three reasons:

​Fixed Disk

• If there is not enough space, fewer programs and data files can be stored on the computer.

• If the disk is not fast enough, performance will suffer when the computer tries to load programs and data files into memory (read operations) or write data from memory to files.

​Fixed Disk

• The computer may use part of the hard disk to supplement system RAM (virtual memory). If the computer does not have much system RAM, it helps for the hard disk to be fast otherwise accessing virtual memory often will reduce performance even more than usual.

HDDs are based on a magnetic disk technology. SSDs use a type of transistor-based memory called flash memory and are much faster than HDDs.

Graphics Processing Unit

• Displaying a high-resolution image to the user requires a lot of processing power, especially if the image changes rapidly, as with video, or uses complicated 3D and texture effects, as with computer games. Consequently, display functions are often performed by a dedicated processor, referred to as the Graphics Processing Unit (GPU). This might actually be part of the CPU package or a more powerful GPU might be provided on a plug-in expansion card.

Network Interface

• Computers, smartphones, and tablets are almost always used as part of a computer network. They can use the network to share information locally and to access data over the Internet. There are two main ways of making a network link:

Network Interface

• Wired network—on a home network, the computer will be connected to an Internet router via an Ethernet port. On a business network, the computer will be connected to the wider network via an Ethernet switch. The Ethernet port in the computer is provided by a Network Interface Card (NIC). Almost all workstation computers come with a NIC on the motherboard (onboard card). Servers may have additional NICs supplied on expansion (or add-on) cards. The connection to the router is made using a cable with RJ-45 connectors on each end.

Network Interface

• Wireless network—most home networks support Wi-Fi radio networking so that computing devices do not have to be cabled to the Internet router to access the network. Most laptops, smartphones, and tablets have built in Wi-Fi adapters. Workstation computers more typically have a Wi-Fi add-on card. Most business networks support Wi-Fi via wireless access points.

Multiple Choice

Which of these is NOT part of a motherboard?

• Various upgrade sockets

• A set of data buses

• A Solid State Drive (SSD

• A chipset of processors

Motherboard Components

• If you open up a PC or a laptop, the main thing you will see is the motherboard (or system board). The motherboard is a Printed Circuit Board (PCB) with some built-in processors (the chipset), sockets and slots for upgradable components (CPU, RAM, adapter cards, disk drives), and wires (buses) to connect them together.

Motherboard Components

• The motherboard determines the upgrade potential of the computer. If a component is not compatible with the motherboard, it cannot be installed. A component may not be compatible with the motherboard either because it does not physically fit in the type of sockets available or because it is too new for the motherboard's chipset to be able to communicate with it.

Motherboard Components

• The motherboard chipset provides "built-in" functions that might otherwise require an adapter card. Most motherboard chipsets support graphics, audio, and network adapter functions. An add-on card may still be used to upgrade those functions though.

Processors

• A microprocessor (usually shortened to "processor") is a programmable integrated circuit—a silicon chip embedded on a ceramic plate. A silicon chip is a wafer of purified silicon doped with a metal oxide, typically copper or aluminum. The doping process creates millions of transistors and signal pathways within an area called the die, which provide the electrical on/off states that are the basis of binary computer systems.

  
  

Processors

• PCs contain a number of processors, but the most important is the Central Processing Unit (CPU). The CPU is commonly described as the "brains" of a computer; in fact, it is better thought of as a very efficient sorting office. The CPU cannot think, but it can process simple instructions very, very quickly and efficiently. A computer is only as "clever" as its software.

Processors

• There have been numerous CPU architectures, developed by the vendors Intel and AMD, and, within each architecture, a number of different models and for each set of models a brand to position them within a particular market segment. For example, budget PCs, laptops, high-end workstations, and server computers would all be served by different CPU brands and models.

Processors

• The model names are used to market a CPU to consumers, but a model may go through several different versions. The "core" used for a version is given a codename, such as "Haswell," "Skylake," "Piledriver," or "Zen." You will see these names used on PC tech websites and in magazines.

Processors (Intel)

• Core—this is Intel's flagship desktop and mobile CPU series. The earliest models (Core Solo and Core Duo) were laptop-only chips. The Core 2 series introduced desktop versions plus 64-bit and multi-core support. The current product line is divided into Core i3, i5, and i7 brands, with i7 representing the best performing models.

Processors (AMD)

• Ryzen/Threadripper and Ryzen Mobile—this brand now represents AMD's pitch for the high-end enthusiast segment, replacing older AMD FX chips.

Processors (ARM)

• CPUs and their chipsets for mobile phones/smartphones and tablets are often based on the ARM (Advanced RISC Machine) microarchitecture, such as the Apple A, Samsung Exynos, and nVIDIA Tegra, derivatives. RISC stands for Reduced Instruction Set Computing. RISC microarchitectures use simple instructions processed very quickly. This contrasts with Complex (CISC) microarchitectures, which use more powerful instructions but process each one more slowly. Intel's microarchitecture is CISC with RISC enhancements (micro-ops).

Processors Features

• The CPU is designed to run software programs. When a software program runs (whether it be an operating system, anti-virus utility, or word processing application), it is assembled into machine code instructions utilizing the fundamental instruction set of the CPU and loaded into system memory. The CPU then performs the following operations on these instructions:

Processors Features

• The Control Unit fetches the next instruction in sequence from system memory to the pipeline.

• The control unit decodes each instruction in turn and either executes it itself or passes it for execution to the Arithmetic Logic Unit (ALU), which does all processes related to arithmetic and logic operations that need to be done on instruction words, or the Floating Point Unit (FPU), which handles all mathematical operations that have to do with floating point numbers or fractions.

Instruction Set (32-64 bit)

• The original version of x86 created in 1978 was designed for 16-bit CPUs. This means that each instruction is 16-bits "wide." The first 32-bit CPU was introduced in 1985 and the x86 instruction set was updated to a 32-bit version, called x86-32 or IA-32 (Intel Architecture).

Instruction Set (32-64 bit)

• The main advantage of 64-bit is the ability to use more system memory. 32-bit systems are limited to addressing up to 4 GB whereas systems with 64-bit CPUs can address 256 Terabytes (or more). A 64-bit CPU can run a 64-bit or 32-bit OS. A 32-bit CPU cannot run 64-bit software.

Instruction Set (32-64 bit)

• Most workstations and laptops now use 64-bit CPUs. Some budget models might come with a 32-bit chip, though this is increasingly unusual. Almost all server computers would use a 64-bit CPU with only very old servers relying on 32-bit. 64-bit also dominates the premium smartphone and tablet sector, though 32-bit is still prevalent on budget and midrange models.

Clock Speed & Bus Speed

• A CPU's clock speed is the number of instructions it can process in one second. As a measure of frequency, this value is expressed in Hertz (Hz). Early processors had clock speeds measured in Megahertz (MHz), or 1,000,000 times faster than 1 Hz. Modern CPUs run at 1 Gigahertz (GHz) or better. 1 GHz is 1000 times faster than 1 MHz.

Clock Speed & Bus Speed

• When Intel or AMD release a new CPU, they produce a range of models clocked at different maximum speeds (2 GHz, 2.4 GHz, 2.8 GHz, and 3 GHz for instance). 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. Dual-core CPUs run slower (up to about 3 GHz) than many earlier single core CPUs (up to about 4 GHz), but deliver better performance.

Clock Speed & Bus Speed

• The core clock speed is the speed at which the CPU runs internal processes and accesses cache. The Front Side Bus speed is the interface between the CPU and system memory. The speed of the bus is usually determined by the memory controller, which might be part of the motherboard chipset or part of the CPU.

Clock Speed & Bus Speed

• While older bus speeds are typically measured in MHz, modern bus types and memory interfaces work at GHz speeds. Also, modern memory designs increase bandwidth by transferring data twice per clock cycle (Double Data Rate) and often by transferring data from two memory modules simultaneously (Dual-channel).

Microprocessing & Dual Core

• Trying to make the CPU work faster by increasing the clock speed has the drawbacks of using a lot of power and generating a lot of heat. A different approach to making a computer system faster 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.

Multiple Choice

Which of these is a hard drive interface standard?

• DOCSIS

• HMDI

• EIDE

• FTTC

Microprocessing & Dual Core

• SMP means physically installing two or more CPUs in a multi-socket motherboard. Obviously, this adds significantly to the cost and so is only implemented on servers and high-end workstations.

Microprocessing & Dual Core

• However, improvements in CPU manufacturing techniques have led to another solution: dual-core CPUs, or Chip Level Multiprocessing (CMP). A dual-core CPU is essentially two processors combined on the same die. The market has quickly moved beyond dual-core CPUs to multi-core packages with four or eight processors.

System and Bus Expansion

• A bus is circuitry that connects the various microprocessors and other components on the motherboard. If you look closely at a motherboard, you will see many tiny wires. These wires are the circuitry that makes up a bus imprinted on the Printed Circuit Board (PCB) that is the basis of a motherboard (there are actually multiple layers of circuitry in addition to what you can see on the surface). A bus carries four things:

Multiple Choice

Which brand of Central Processing Unit (CPU) would be found in a 32-bit server?

• Opteron

• Phenom

• Pentium

• Turion

System and Bus Expansion

• Data—the information being transferred between components.

• Address information—where the data is located in memory.

• Timing signal—as different components can work at different speeds, the system clock synchronizes the way they communicate over the bus.

• Power—electricity to run the component.

System and Bus Expansion

• A PC system has two main types of bus: the system (or local) bus and the expansion bus.

  • The system bus, also referred to as the Front Side Bus (FSB) or local bus, provides connections between the CPU and system memory.

  • The expansion bus, also called the Input/Output (I/O) bus, provides connections between the CPU and add-on components, which can be integrated onto the motherboard, installed as expansion cards, or connected as peripheral devices.

System and Bus Expansion

• The architecture of the expansion bus depends on what generation the motherboard and CPU platform are. Broadly speaking, since 1993, PC architecture has been based on one of Peripheral Component Interconnect (PCI), PCI with AGP (Accelerated Graphics Port), or PCI Express (PCIe).

Multiple Choice

What type of Network Interface Card (NIC) uses the 802.11b protocol?

• An Ethernet card

• A Bluetooth Personal Area Network (PAN) card

• A Near Field Communications (NFC) card

• A wireless network (Wi-Fi) card

System Cooling

• As a by-product of pushing electric current through the various electronic components in the computer, the system generates heat. The faster the components work, the more heat is produced. Excessive temperatures can cause the components to malfunction or even damage them. One of the most significant problems with CPUs (and RAM chips and graphics cards) is their thermal output.

System Cooling

• While Intel and AMD are both focusing on making new CPU designs more thermally-efficient, all CPUs require cooling. Also, a specific CPU model requires a specific cooling system, as some run hotter than others; the old Pentium 4 CPUs being a good example.

Multiple Choice

Which is NOT carried by the expansion bus?

• Add-on component data

• System memory data

• Timing signal

• Address information

Multiple Choice

How are onboard and add-on Network Interface Cards (NIC) different?

• Add-on cards use a different cable connector than onboard cards.

• Onboard cards and add-on cards operate in the same way.

• Onboard cards are much faster than add-on cards.

• Add-on cards are much faster than onboard cards.

Heatsinks and Thermal Paste

• A heatsink is a block of metal with fins. As the fins expose a larger surface area to the air around the component, a greater cooling effect by convection is achieved. The heatsink is "glued" to the surface of the chip using thermal paste, also referred to as thermal grease or compound, to ensure the best transfer of heat.

Heatsinks and Thermal Paste

• A heatsink is a passive cooling device. Passive cooling means that it does not require extra energy (electricity) to work. In order to work well, a heatsink requires good airflow around the PC. It is important to try to keep "cable clutter" to a minimum and to keep the PC interior free from dust.

Heatsinks and Thermal Paste

• As heatsinks are bulky objects with a lot of height, they cannot be used in laptops or other mobiles. Computers with thin cases use a heat spreader instead. This is a flat tube with liquid inside. As the component heats up the liquid, it moves to another part of the tube and is cooled down by a fan or other type of convection. The cooler liquid then passes back over the component, heats up again, and moves away, creating a constant cooling cycle.

Multiple Choice

What part of the Central Processing Unit (CPU) determines whether it is 32-bit or 64-bit?

• The CPU data bus

• The amount of Random Access Memory (RAM) in the computer

• The size of the hard drive

• The General Purpose (GP) register

Fans

• Many PCs have components that generate more heat than can be removed by passive cooling. A fan improves air flow and so 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 vents in the front of the case over the motherboard and expel warmed air from the back of the case.

Liquid-based Cooling System

• PCs used for high-end gaming, those with twin graphics cards for instance, and with overclocked components 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.

Multiple Choice

Which type of laptop would NOT use a 64-bit Central Processing Unit (CPU)?

• A laptop that uses an AMD processor instead of Intel.

• A budget laptop designed for a low price tag.

• A laptop intended for gaming purposes.

• A laptop with less than 4 GB of system memory.

Liquid-based Cooling System

• Liquid-based cooling 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. On the downside, liquid cooling makes maintenance and upgrades more difficult, requires comparatively more power to run, and is costly. Liquid cooling is an active cooling technology as the pump requires power to run.

BIOS and UEFI System Firmware

• When a computer is powered on, it needs some standard means for the CPU to start processing instructions and initialize the other components. This is referred to as bootstrapping or more simply as booting. The bootstrapping process occurs before the operating system software is loaded and is enabled by a low-level operating system called firmware..

Multiple Choice

What is the main difference between a Solid State Drive (SSD) and a Hard Disk Drive (HDD)?

• The SSD uses flash memory and the HDD uses platters.

• The SSD size is usually much larger than a HDD

• The SSD uses platters and the HDD uses flash memory.

• The SSD is much cheaper per megabyte than the HDD.

BIOS and UEFI System Firmware

• The BIOS (Basic Input/Output System) is one example of PC firmware. It provides industry standard program code to get the essential components of the PC running and ensures that the design of each manufacturer's motherboard is PC compatible.

BIOS and UEFI System Firmware

• Newer motherboards may use a different kind of firmware called UEFI (Unified Extensible Firmware Interface). UEFI provides support for 64-bit CPU operation at boot, a full GUI and mouse operation at boot, and better boot security. A computer with UEFI may also support booting in a legacy BIOS mode.

Multiple Choice

Which of the following is a limitation of a 32-bit processor in a workstation?

• It does not recognize external hard drives that exceed 1 TB of storage.

• It does not support USB 2.0 or 3.0 devices

• It is incompatible with older versions of Windows.

• It cannot use more than 4 GB of system memory.