Introduction
This guide will describe the inner components of a desktop
computer. Many people today are not entirely sure how computers work or what
components there are in modern computers. This leads some to believe that some
certification or degree is required to understand how a computer works or is
built. However, building a computer is much like building a creation with
Legos. A desktop computer is a stationary computer that is often connected to
external peripherals, such as a keyboard, mouse, and monitor. A modern desktop
computer usually consists of a case, motherboard, CPU, HDD, RAM, GPU, and power
supply. This guide will help to understand what a desktop computer is composed
of.
Case
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| Figure 1: The Corsair Air 540 Case |
Many people believe that while computer cases may look
different on the outside, they are all the same on the inside. While this may
appear to be true, there are actually several different computer
case form
factors. There have been many form factor specifications created in the past.
However, today only three are still commonly used. These are the Advanced
Technology eXtended (ATX), Micro ATX (mATX), and Mini-ITX form factors. Each of
these form factors has its own dimensions in order to fit all of the needed
components. Figure 1 shows a popular computer case made to fit ATX and Micro
ATX motherboards. The computer’s motherboard also depends on the form factor of
the case, as it governs the size of the Printed Circuit Board (PCB).
Motherboard
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| Figure 2: A motherboard with labelled connections |
The motherboard’s main function is just what the name
suggests. As Figure 2 shows, the computer’s motherboard serves as a host to
which all other components plug into. Motherboards come in all shapes and sizes
depending on the type of components that can be plugged into it. This is why
the case’s form factor is important. If the form factor of the motherboard does
not match the form factor of the case, then the motherboard will not fit into
the case properly. The only exception to this is the mATX form factor, which
can be properly installed in an ATX form factor case. This is like a new stereo
system having both a CD and tape player, but the old tape player not being able
to play CDs. ATX form factor cases have mounts for mATX motherboards, but mATX
cases do not have mounts for ATX motherboards. Another important specification
to be aware of on the motherboard is the Central Processing Unit (CPU) Socket
specification. This will narrow down your choices as to which CPU you can use
in your computer. Read more about why this is important in the next section.
Central Processing Unit (CPU)
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| Figure 3: A pair of Intel CPUs |
The Central Processing Unit, or commonly referred to as the
CPU is the brains of the computer. Its primary function is to manage all other
parts of the computer and to process all information. Just like an engine in a
car, the CPU has many different models and generations with varying degrees of
power. When a new generation of CPU is released to the public, there is a
hardware change in the socket on the motherboard that makes it impossible to
use older CPUs. This is why it is so important to make sure that the socket
specification on the CPU matches the one on the motherboard. It is similar to
trying to plug in an American appliance into a wall outlet in the UK without an
adapter. It simply won’t work.
Storage
A computer has many types of memory. However there is only
one type of memory that users will interact with, and that’s non-volatile
memory. Non-volatile memory is a technical term for any memory that will
persist even after the computer itself is powered off. Today, the main type of
non-volatile memory is the hard drive. The hard drive (HDD) is a storage device
that stores large amounts of data on metal platters that commonly spin at
either 5400 or 7200 RPM. When researching which hard drive to buy, it is
important to see what connector it uses. For most desktop/ internal hard
drives, the connector will use the SATA (Serial ATA) standard. This is a
connector that is included on every modern motherboard. In addition to the SATA
connector, there is a power connector on the hard drive, and a compatible cable
on the power supply of the computer.
Random Access Memory (RAM)
 |
| Figure 4: A stick of desktop RAM |
Random Access Memory, or simply RAM, is a type of volatile memory.
This is not to say that it is unreliable, but that when the computer is turned
off, the RAM loses the data that is stored on it. When compared to a hard
drive, RAM is immensely faster. Comparing RAM to hard drive speeds is like
comparing the speed of a Bugatti to that of a snail. When data is loaded from
the hard drive, it is loaded into RAM so that it can be accessed and modified a
lot faster than if it was constantly being loaded off of the hard drive. Today,
there are two types of desktop RAM: Double Data Rate Type 3 (DDR3) and Double
Data Rate Type 4 (DDR4). RAM is governed by the specification on the
motherboard, with no compatibility between versions.
Graphics Processing Unit (GPU)
 |
| Figure 5: An ASUS GTX 970 graphics card |
Another component commonly seen in desktop computers today
are Graphics Processing Units, called video cards or GPUs. While most modern
CPUs have the functionality of processing graphics by themselves, the
processing power does not compare to that of a dedicated graphics card. Having
a dedicated graphics card allows the computer to be able to process most
graphics-related calculations a lot faster than a CPU can. Video cards are
mostly marketed to those who want extra computational power to be able to run
video games at higher settings and professionals who use special programs that
make use of the video card’s computational abilities.
Power Supply
Last, but certainly not least, a computer needs its own
specialized power supply. Generally, unless otherwise specified by the case, an
ATX power supply is used to power a computer. There is only one detail to look
out for when researching power supplies, and that is how many watts it outputs.
There are many calculators that can determine what wattage power supply is
needed, but most people need a 400W power supply without a video card and 500W
power supply with a video card at the minimum.
Bibliography
Corsair. (n.d.). Carbide Series® Air 540 High Airflow ATX
Cube Case [Digital image]. Retrieved March 24, 2016, from
http://www.corsair.com/en-us/carbide-series-air-540-high-airflow-atx-cube-case
Intel. (n.d.). Intel Devil’s Canyon Processor High-Res Shot
[Digital image]. Retrieved March 24, 2016, from
http://wccftech.com/intel-devils-canyon-processors-officially-announced-core-i74790k-core-i54690k-march-4-ghz-barrier/
What is a Motherboard - ATX
motherboard layout [Digital image]. (n.d.). Retrieved March 31, 2016, from
http://www.what-is-my-computer.com/what-is-a-motherboard.html
C. (n.d.). Vengeance® — 4GB Dual
Channel DDR3 Memory Kit (CMZ4GX3M2A1600C9) [Digital image]. Retrieved March 31,
2016, from
http://www.corsair.com/en-us/vengeance-4gb-dual-channel-ddr3-memory-kit-cmz4gx3m2a1600c9
A. (n.d.). ASUS Strix GeForce GTX
970 [Digital image]. Retrieved March 31, 2016, from
https://www.asus.com/us/Graphics-Cards/STRIXGTX970DC2OC4GD5/
