Basic Parts Of Computer System Unit

By Rex Resurreccion Jan 01, 2020
Build your desktop computer from scratch

In this tutorial we will go over the basic parts of a computer system unit. I have also mentioned at the end of this tutorial the several build types and its hardware requirements for your reference.


First on our list is the motherboard. This is the central point that connects all devices and components of your system unit like the processor, memory and hard drive.

Choosing A Motherboard

There are several factors that has to be considered when buying your motherboard. However, we will cover here the most important specifications.

  1. Brand of Processor – When it comes to branding, there are two major players in the market, Intel and AMD. Intel has more number of users in the market, and AMD tends to be cheaper. Similarly, both are reliable and the features are sometimes equivalent.
  2. CPU Socket Type – The socket type will determine the model or series of processor that can fit in the motherboard.
  3. Form Factor – Hardware design that defines the size, shape and physical specifications. For example, an ATX motherboard has different sizes of standard, mini and micro.
  4. DIMM Slot – How many RAM sticks the motherboard can hold. Make sure you have an extra slot for your memory in case you need to upgrade in the future.
  5. Chipset – The chipset controls the communication between the CPU, RAM, Drives and other I/O Peripherals.
  6. PCI Slot – To use a dual monitor you need a PCI Express slot for the Video Card.
  7. SATA Ports – More ports for the Hard Drive and CD/DVD-ROM the better. If you plan to setup RAID for redundancy then make sure you have an extra ports for multiple drives with a 6Gb/s interface.
  8. I/O Peripherals – Motherboard has a standard I/O slot for PS2, HDMI, DVI, VGA, LAN, Audio Jacks and USB 2.0 and 3.0. It should be able to support the Front Panels on the computer case. Check the maximum LAN speed if the wired network connection is a requirement.
  9. On Board RAID – Does the motherboard supports RAID configuration already.


Second on our list is the Processor or Central Processing Unit (CPU). The CPU is where all the data and commands are queued and give instructions to the computer hardware.

Intel and Advanced Micro Devices (AMD) are the two primary manufacturers of computer microprocessors.

Choosing A Processor

  1. Socket Type – It has to be compatible with the socket type of the motherboard.
  2. Cores and Threads – The number of program/application and task a computer can run simultaneously depends on this. The more cores and threads the better performance you can get from your computer, although this comes with a price tag, that’s why it is important to balance your required specs and budget.
  3. Base and Max Frequency – This is the speed of the processor. If you plan to overclock your computer, be sure to check the max turbo frequency, although I suggest to give it a good amount of Cores and Memory instead.
  4. Cache – Caching will help to improve the processing speed of the CPU by accessing the data from its cache memory instead of retrieving this all the way back to the main RAM.
  5. 64-Bit Support – It is best to use a 64-Bit processor. This will allow your computer to support Operating System and Software that require a 64-Bit architecture.
  6. Hyper threading – Special builds that will run application with heavy load and require more tasks to be threaded in parallel will benefit on this feature.
  7. Virtualization – This technology is necessary if you plan to run Virtual Machines in your computer.

Random Access Memory

RAM is used to store data from a running program for faster read and write. While the memory is good for storing temporary data, it is also volatile and all information will be removed when the computer is turned off.

Choosing A RAM

  1. DDR Type – Double Data Rate. DDRs differs in pins (DIMM), frequency, speed and voltage. Make sure that the motherboard has the DIMM slots to support the quantity of RAM sticks you will need.
  2. Capacity – Higher capacity will give your computer a boost in processing certain types of operations that reads and writes more frequently in memory.
  3. CAS Latency – Column Access Storable Latency. RAM with lower latency the better.

Hard Drive

Hard Drive is a storage device in the computer that stores all your digital files. Unlike the Memory, hard drive data are persistent, thus the data will still be accessible after a computer reboot.

Choosing A Hard Drive

  1. HDD vs SSD – Hard Disk Drive vs Solid State Drive. SSD does not have the mechanical moving parts of an HDD (rotating disks, spindle and motor), thus it makes faster read and write. The price per GB of an SSD is more expensive. If the read and write speed is not critical for your job, I suggest installing an HDD to get more disk space in lesser cost.
  2. Capacity – If you are frequently saving large files such as video, photos and programs then you need a good amount of storage. Nowadays it is normal to use 500GB to 2TB drive on a desktop computer, depending on your budget and usage you can even go higher.
  3. Form Factor – Physical size of the drive. Regular size of a drive is 3.5” for desktop and 2,5” for laptop.
  4. RPM – Revolutions Per Minute. HDD with higher RPM will have faster data transfer rate. I suggest at least a 7200 RPM drive.
  5. Interface – Type of bus supported by the motherboard. SATA 6.0Gb/s drives is a safe choice for personal computer and workstation. SAS will perform better for enterprise computing that relies on high speed and high availability.

Power Supply

Power Supply provides electric power to the Motherboard, Processor, Storage Devices, CD/DVD-ROM, Fans and all parts of the system unit.

Choosing A Power Supply

  1. Wattage – Make sure that it can support the power requirements your hardware.
  2. Form Factor – The type of motherboard. Does it use an 20/24 pins and 4/8 pins main connectors.
  3. Modular – If you prefer to detach power cables that are not being used to keep your wiring neat and tidy.
  4. Connectors – How many SATA, PCI-Express (optional), Fan power connectors it can support.

Video/Graphics Card

Graphics Card is optional on this build. If you are building a gaming computer, bitcoin mining, or anything that require special graphics processing then you will need a good Graphics card. Some motherboard also has Integrated Graphics processing capability.

If you do not need any graphics processing but want to have dual monitor for display, then a low end Video Card that has at least two to three display ports will be sufficient.

Computer Case

Last but not the least is the case or chassis. This is the enclosure of the computer hardware. All the computer parts mentioned in this tutorial will be going inside the casing.

Choosing A Computer Case

  1. Type of Case – This will depend on the form factor of the motherboard. Full or Mid Tower for a desktop computer.
  2. Fan – A good ventilation will protect the hardware from overheating.
  3. Internal Drive Bays – I suggest at least four drive bays. To setup RAID for failover, it will need two or more drives. For instance, RAID 1 uses two drives and at least four drives for RAID 10 .
  4. Front Panel – It would be nice to have a USB port, Audio, Mic, power and reset buttons in front of the case for convenience.

Which Computer Parts Should Get More Resource?

We have gone through the basic parts of computer system unit , to determine which component should get more share in your budget it all depends on what type of computer you are going to build.

  • General Purpose/Internet Browsing – Basic computer build with a decent amount of Processor and Memory will perform just fine.
  • Gaming – More Video Card, Memory and an optional SSD
  • Programming/ Workstation – Invest on Processor, SSD and Memory
  • Video Editing – More storage space, a HDD type of hard drive is okay and a boost on CPU.
  • Home Theater – HDD for more storage space and optional Graphics Card.
  • Bitcoin Mining – Processor, Graphics Card and Memory.
  • Website Server – Processor, Memory, More Storage Space (Optional)


To summarize the basic parts of computer system unit , you will need a Motherboard, Processor, RAM, Hard Drive, Power Supply, Video Card is optional and a Computer Case.

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