How to Build a Personal Computer

I’ve noticed some folks around here use personal computers (or “PC’s”, as the kids call them these days) but sometimes they buy them pre-built or send them off to a store to get parts upgraded. Well, you can save yourself a lot of time and effort by doing your own repairs and, as we will discuss today, you can even build your own PC from scratch. I know, right?

There is nothing wrong with buying a PC “off the shelf”, so to speak; sales and offers make the market very competitive and convenience is often king in these matters. Also, laptops/notebooks aren’t really all that upgradeable, so I will be sticking to desktop PC’s for the bulk of this article. However, if you fancy popping some more RAM in, or want to improve your graphics card, it’s often literally a two minute job. So let’s get stuck in.

The Case

No matter what parts you buy for your rig, they will need to live somewhere, so the case is just as important a component as any other. PC’s come in different sizes, or “form factors”, which ties in directly with components like the motherboard (more on that later), but the main ones are:

ATX – this is the biggest and the most common. Sometimes called “full tower” or just “tower”.

Micro-ATX – as the name suggests, this is a smaller version of ATX. It has the same functionality (I have an M-ATX motherboard in a normal sized case) but it is more compact.

Mini-ITX – smaller still.

When you are choosing your case, it is important to make sure that your other components will fit in it and consider where your PC will be placed. For the sake of simplicity, I will be assuming that you are using an ATX case and parts for the remainder of this article. Although aesthetics are an important part of choosing your case, it is also worth looking at functionality too. A good case will have room to expand, USB and audio ports that are easy to access, space to route wiring or additional fans, etc. Also, bear in mind that optical disc drives are not often considered in modern PC cases. You might scoff at this but a lot of people still like to use their PC to watch DVD’s/Blu-Rays or listen to CD’s; my case has no provision for an internal disc drive, only a USB one.


The Motherboard

The motherboard is the part of your PC that most of the other components will live on, hence the name. As mentioned above, they come in different sizes but there are two main “flavours” as well; AMD or Intel.

When purchasing a motherboard, you will see the “socket” mentioned prominently. This indicates what processor the motherboard is compatible with, and so you should make sure that whatever parts you buy will work with the motherboard.

Common AMD platforms are AM4 (this is the socket that Ryzen processors work with), TR4 (this is Threadripper, a high-end processor) or the slightly outdated AM3.

Intel have slightly more obtuse names but common sockets are LGA 1151 (or Socket H4) or the older LGA 1150.

You will also need to consider the chipset; this is the “bridge” between the processor and the rest of your PC components. If this all sounds like a load of jargon, the main takeaway should be that whatever motherboard you buy, make sure that you read up on the other components it is compatible with. An AMD Ryzen processor will not work in an Intel motherboard, etc.


The Processor

The processor (or CPU; Central Processing Unit) is both a modern miracle and the beating heart of your new PC. Again, your choice of processor is directly linked to your choice of motherboard and this, in turn, will affect some other components.

For PC’s, there are two main manufacturers of CPU’s; AMD and Intel again.

AMD have recently brought out a range of CPU’s called Ryzen. Ryzen processors are currently in their second generation (Ryzen 2xxx) with a third on the way. AMD processors, historically, have been the underdog to Intel’s established pedigree. I have a first generation Ryzen myself and I think they are excellent value-for-money. When choosing a processor, consider what you will be using the PC for, cost, longevity (buying an old CPU now will make it more likely you need to upgrade in the future), etc.

Intel are a household name and statistically the most common choice. They tend to be a little more expensive but, for some folks, you can’t put a price on pedigree.

It is also worth noting that Ryzen processors come with their own cooling apparatus; if you purchase an Intel processor, you will also need to buy the relevant CPU cooler to keep the air flowing over it. This is worth factoring in when it comes to cost.

When considering your CPU cooler, it is important to make sure it fits the CPU socket correctly, will physically fit inside your case (some of them are absolute units) and whether or not you intend to tinker with the default settings of the CPU or not (overclocking).



Memory, Random Access Memory or RAM is a dull but important part of any PC build. The current standard is DDR4, which works with Intel or AMD processors, but DDR3 is still out there in a lot of PC’s. The rule of thumb is the more RAM you have, the more intensively you can use your PC.

For gaming, I get away with 8GB (gigabytes) but, if you’re building a new PC, I think 16GB is pretty much required if you intend to use the system in the future. More than 16GB is really only required if you use your PC for things like video editing or image manipulation, design etc.

RAM comes in different speeds, too. The faster the better, though it’s debatable how much of a difference the end user will notice. Again, double check that your motherboard and CPU are compatible with the speed and type of RAM you get. Ryzen processors like faster RAM and AM4 motherboards can let you “overclock” (run above the factory speed) your memory to some extent, so make sure you are getting the most out of your components.

RAM prices have shot up in recent years; 16GB of DDR4 is about £110/$140 at the moment. Prices are starting to normalise a little but it wasn’t that long ago that buying RAM was just something you did for about £40.


The Graphics Card

If you want to use your PC for advanced 3D games, you will require a graphics card. Some motherboards have a graphics processor (or GPU) integrated into the chipset. These are improving all the time and can handle 2D games and moderate 3D games pretty well. AMD have also been tinkering with combining their CPU’s with GPU’s and you can play games like Overwatch, Grand Theft Auto V or even DOOM 2016 using only the CPU’s processing power.

However, for serious gaming you will need a dedicated graphics card and they come in two main flavours; AMD or Nvidia.

AMD’s Radeon range (Radeon was previously made by a company called ATI, until AMD snatched them up) tend to run a bit hotter, use more power and, in my humble opinion, are a little overpriced.

Nvidia are currently on their 20 series of cards, but the 10 series are still very much the most common choice for gaming these days. I run a GTX 1080 myself. It is worth mentioning that your make of graphics card is entirely independent from your make of CPU; I have an AMD processor with an Nvidia GPU, you’ll notice.

When considering a graphics card, it is a good idea to look at games or programs you intend to use and see what the requirements are. A GPU is often the most expensive part of any PC build (especially if you are gaming), but bear in mind that system requirements are always increasing, so spending now will ensure that you can still use your rig in years to come.



Storage is always an issue with any computer; it can sometimes feel like you never have enough.

There are two main choices for PC storage these days, Hard Disk Drives (HDD’s) or Solid State Drives (SSD’s).

HDD’s are cheaper and often larger in capacity but they contain moving parts, so are slower on the whole and statistically more likely to fail. However, if you buy a good quality HDD at a high speed (7200 rpm or above) then they are perfectly fine for everyday use.

SSD’s are coming down in price and increasing in capacity all the time. A common technique amongst PC users is to have a smaller SSD as the home for your operating system and use a cheaper, large HDD for the bulk of your storage. This way, your PC will load up very quickly but you can still store large files or games on a much more capacious drive. Also, it’s worth pointing out that you can simply add more drives to your PC in the future, if required.

SSD’s also come in a “stick” format called M.2. These require a special slot on the motherboard but they function the same as a normal SSD drive and are a convenient way of saving space inside your PC case.

The main way of connecting storage is via a cable system known as SATA. There are other methods of interfacing (notably PCI-E) but we will not be covering them here.


Power Supply

The power supply unit, or PSU, is an important but often overlooked part of any PC build. They are how mains voltage is converted to a usable power form for your electronic components.

PSU’s are rated by wattage and they often have a “colour” rating as well. To work out what power rating you need, there is a handy online calculator you can use here but for a no-frills PC build, 500/550 watts is the normal point of entry.

The colour rating (bronze, silver, gold, etc) is a measure of efficiency and the higher the rating, the less energy will be wasted as heat. Because of this, higher rated PSU’s tend to be viewed as better in build quality and therefore more reliable, though this is no guarantee at all. You really don’t want to scrimp on the power supply; a bad one can do more than ruin your day, it can wreck your PC completely.

PSU’s used to come with a fixed amount of leads and connectors to attach to your components but modular versions are becoming more and more popular. These tend to be a little more expensive but they are neater to install, since you only need to use the cables you require.

Although this applies to any PC part that uses a fan, it is worth considering noise when purchasing a PSU as well. Some are marketed as being quiet/silent, which could be a factor when choosing a component.




So now you have the parts for your PC, but you will need some other stuff to actually use it.

The main requirement is, of course, a display. Though you can use any HDMI TV set as a display, this is often not practical and there is an argument to be had that a TV is inferior to a dedicated PC display. This is mainly due to input lag, the perceived time between you interacting with your PC and the image being displayed on screen. This is measured in milliseconds (ms) and the lower this figure, the better.

There are two main considerations with a display, resolution and refresh rate. When it comes to resolution, it is worth considering what you intend to use the PC for and the components inside; it is probably not feasible to buy a 4K display if you have gone for a low-end graphics card, for example.

Likewise, a high refresh rate (indicated in Hz) is going to be wasted if you only use your PC for web browsing or watching movies.

Something you will see mentioned in regards to displays is FreeSync or G-SYNC. These are effectively the same thing but they are both methods of ensuring that your display synchronises with your graphics card efficiently, preventing a graphical glitch known as “screen tearing”. The rule is if you have an AMD/Radeon graphics card, you want a FreeSync display; if you have an Nvidia card, you want G-SYNC compatibility. Neither are required but it is worth noting when considering your purchase.

EDIT: Dan Pierce rightly pointed out that I forgot to mention networking, which you will definitely need if you want to get on to the Internet! Most motherboards have some kind of Ethernet connection these days (though always check) but if you want to go wireless, you will have to check if your motherboard has an onboard option. If not, you can either purchase an internal WiFi card that slots into your motherboard (provided you have the space) or you can go for a dongle that connects via USB.

Finally, you will need a mouse and keyboard. Again, consider what you will be using the PC for. For gaming, consider a mouse with adjustable speed settings. This allows you to adjust sensitivity on the fly, depending on the requirements of the game. A popular trend with keyboards these days are mechanical switches. These are, supposedly, more satisfying to use and provide greater tactility. Naturally, they are slightly more expensive than the standard “soft” switches favoured by modern membrane keyboards. However, if you intend to do a lot of writing on your PC, you might find that a mechanical keyboard is easier to type with.


I have barely scratched the surface here, let alone discussed the actual mechanics of physically building a PC, but I hope this article demystifies the baffling world of computer hardware somewhat.

A big part of computer culture is arguing about things, too, so feel free to thoroughly discredit me in the comments below.