Introduction
This guide will describe the inner components of a desktop
computer. Many people today are not entirely sure on 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 usually connected to external
peripherals, usually a keyboard, mouse, and monitor. A modern desktop computer's insides usually consists of a case, motherboard, CPU, HDD, RAM, GPU, and power supply.
This guide will help to understand what these parts do.
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 all 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 and amount of components that can be plugged into it. This is where
the case’s form factor becomes 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 an 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)
The Central Processing Unit, or commonly referred to as the
CPU is the brains of the computer. Its
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| Figure 3: A pair of Intel CPUs |
Storage
In a computer there are many types of memory. However there
is only one type of memory that users will interact with, and that is
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 will also be a power connector on the hard drive, which there
is a cable for on the power supply of the computer.
Random Access Memory (RAM)
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| Figure 4: A stick of desktop RAM |
Random Access Memory, or simply RAM, is a type of volatile
memory on a computer. 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. While
it may seem confusing as to why RAM is needed when it will lose its memory when
the computer is turned off, it is indeed very important. 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). What RAM is used is also governed by the specification
on the motherboard, with no compatibility between versions.
Graphics Processing Unit (GPU)
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| 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 user to be able to process most
graphics-related calculations a lot faster than a CPU can. Today's video cards also make use of a PCIe x16 interface, which can be seen in Figure 2. This interface allows for extremely fast data exchange rates between the video card and other components on the motherboard. Video cards are
mostly marketed to those that want extra computational power to be able to run
video games at higher settings and professionals that 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.
Conclusion
With this information you should now have a basic understanding of the components that make up a modern desktop computer. Since the computing industry is constantly making advances in technology, some of this information may become outdated in the future as new specifications and standards are released. However, this information is currently a good source for understanding the basics of a computer's components.
Sources
- 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/
