How To Build A Computer From Scratch: Hardware Basics

How To Build A Computer From Scratch: Hardware Basics

Building a computer from scratch gives you the perfect machine for your needs, but it can be daunting the first time around. Over the next few days, we’ll be taking you through the buying, building and installation process step-by-step. Today, we’re going to start with a little computer hardware basics.

PC picture by Shutterstock

While you could just go to the store and buy a pre-built desktop, you might find that you’re happier with a custom-built machine. Building a PC from the ground up means it’s perfectly crafted to fit your needs, whether you’re a hardcore gamer, video editor extraordinaire, or you’re just trying to build a low- or high-powered home theater PC. In some instances, you may save some money, but in all instances you’ll have accomplished a project that you’ll benefit from for years—a pretty great feeling in and of itself. That said, building is much more time consuming than buying, and your first time through, it can be daunting. In this series, we’ll be walking you through building your first (or second, or third) computer from start to finish.

Today, we’ll be talking about the first step in any computer build: brainstorming what kind of machine you’re looking to make and what that means for your hardware.

The Types of Machines and their Ballpark Costs

The the first thing you need to do is come up with a very, very rough idea of what kind of performance you want from your machine. The easiest way to do that is to split builds it up into three general categories:

  • Low Performance: If you’re looking for a simple PC for web browsing, email checking, or video watching, a low performance machine is probably the way to go. These machines are small, don’t draw a lot of power, and are usually pretty quiet, which is great (though they obviously sacrifice performance for those perks). Nettops, home theatre PCs, and (on a more extreme level) home servers also fit into this category. Most custom-built low performance machines range from $400 to $600.
  • Middle of the Road: This is a great option for the majority of users, especially since you can stretch the machine’s power and your budget to fit almost any scenario. Middle of the road machines will sit in a smaller computer tower, with enough power to play some games and run more than a few programs at once. If you’re looking for a multipurpose computer that won’t break the bank, this is where you want to go. Middle of the road machines can vary quite a bit in price, but in general they range from $500 to $900.
  • High Performance: These are the big guns. Generally, users with high performance computers are doing things that are more resource-intensive: converting and editing large amounts of video, playing the latest and greatest games at high settings, running other operating systems in virtual machines, and so on. Be prepared to shell out a bit of cash, use a lot of electricity, and devote a lot of space to this machine. Again, there’s a good range here, but typically a high performance machine will cost anywhere from $900 to infinity and beyond.

Note that most of those price ranges don’t include extras, like a keyboard and mouse, monitor, speakers, and other such things. Chances are, if you’ve ever owned a computer before, you already have some of those lying around.

The Parts That Make Up A Computer (And What They Do)

Every fully-functioning computer is made of the same basic components, and in this section, we’ll walk through the basic hardware you’ll need for your first build. We’re still just talking about “things to consider” here—we’ll get down to the nitty-gritty of picking out specific parts in the next lesson. Here, we just want to point out what the important components are, and which ones are the most important for certain builds.

The Processor

How To Build A Computer From Scratch: Hardware Basics

The Processor (CPU) is the “brain” of your computer, the thing that carries out the tasks you give it. Better CPUs can perform more tasks at once, and perform them faster. That said, not everyone actually takes advantage of their processor’s full speed, so the high-end models are only really crucial if you’re performing intensive tasks like video editing, video conversion, compiling code, or (to a lesser extent) gaming. It’s also one of the most expensive parts of a machine, so if you aren’t performing these types of tasks, you definitely don’t need to worry about buying the latest and greatest.

The Motherboard

How To Build A Computer From Scratch: Hardware Basics

The motherboard connects all the other components to one another, and is the physical base upon which you build everything else. It contains a lot of your machine’s core features, like the number of USB ports, the number of expansion cards you can put in (such as video, sound, and Wi-Fi), and also partially determines how big your computer will be. Which motherboard you pick will depend on whether you build a low, medium, or high performance machine and how advanced of a user you are.

The Case

How To Build A Computer From Scratch: Hardware Basics

The case holds all of your computer’s parts together. For the most part, a case is less about features that affect how your computer runs and more about features that affect you and your home—that is, how quiet it is, how large it is, and of course, how it looks in your office. Still, it’s an important consideration that is dependent on your other choices, so you might want to think about what you want in terms of a case before moving on to the shopping step.


How To Build A Computer From Scratch: Hardware Basics

RAM, or Random Access Memory, is like your computer’s short-term memory. It stores data your computer needs quick access to to help your programs run faster, and help you run more programs at one time. Thus, if you run a lot of programs at once, you’ll want a computer with more RAM. If you use virtual machines, you’ll want even more RAM, since it has to run its own programs in addition to yours.

The Graphics Card

How To Build A Computer From Scratch: Hardware Basics

The Graphics card, or GPU, is a processor specifically designed to handle graphics. It’s what you hook your monitor up to, and it’s what draws your desktop and your windows on the screen. Some motherboards come with a GPU already integrated, which is enough to manage your desktop, but usually not enough for playing 3D games. For those, you’ll need a dedicated graphics card, since it can do the legwork needed to draw those complex images.

The Hard Drives

How To Build A Computer From Scratch: Hardware Basics

Your hard drive—not to be confused with memory (RAM)—stores all of your data, ranging from your operating system to your documents, music, and movies. If the RAM is your computer’s short-term memory, your hard drive is the long-term memory. It stores the things you want to keep around for awhile. The kind of hard drive you choose will be determined mainly by how much data you need to store, but certain kinds of hard drives (like solid state drives) can also affect your computer’s speed.

The Optical Drive

How To Build A Computer From Scratch: Hardware Basics

An optical drive, more commonly known as a CD or DVD drive, is what you’ll use to read CDs, DVDs, and even Blu-Ray discs. Not everyone needs an optical drive in his/her computer, but since they’re cheap, there’s little reason not to have one.

The Power Supply

How To Build A Computer From Scratch: Hardware Basics

The power supply directs electricity to the other components in your machine. Generally speaking, if you have a high performance computer with a fast processor, a graphics card, and a few hard drives, you’ll need a higher wattage power supply than you would if you were building a low-end PC. This is probably the last component you’ll shop for, once you’ve nailed down your other parts and how much electricity they’ll require.

Other Parts to Consider

How To Build A Computer From Scratch: Hardware Basics

While these are the main parts almost every computer has, you probably have other needs. For example, if you’re going to use Wi-Fi to access the internet instead of wired Ethernet, you may need to buy a Wi-Fi card. If you take a lot of photos, it’s probably worth getting an internal SD card reader for easily loading your photos onto your computer. If you have any Bluetooth peripherals, you might consider an internal Bluetooth card, and if you video chat with friends, you’ll want to pick up a webcam.

And, as we mentioned before, if you don’t already have them, you’ll need a monitor, keyboard, and mouse.You may even want some extra fans or water cooling parts to optimize the cooling in your PC. These are just a few of the extra things you could use, so really think about what you’ll be using this computer for and what other parts you need to buy so you don’t have to take an extra trip to the store (and so you can better budget your money).

Sit back and ponder how you use your current computer, how you’re going to use your new computer, and what that means for the components listed above. If you’re going to do a lot of gaming, a high-end processor and video card are crucial. If you’re building a home theater PC, you’ll want a “good enough” video card, a low-end processor, and a large hard drive to store all your movies. Once you’ve figured it out, come back for our next lesson tomorrow night, where we’ll talk about how to actually shop for the parts you need to build your computer.

Stay posted for Part 2, where we’ll look at choosing and buying your parts!


  • For video editing and graphic design would a Mac perform better than a windows machine in the same price range?

    • Definitely not!
      For the price of a Mac you could build yourself an incredible super computer.

      Macs are just massively overpriced Intel computers with a different operating system.

      About seven years ago when the G4 Power Macs were around, yes, they were great (but still very expensive) machines. But these days. . . its just what I said above.

  • Quite often one hardware item selection will determine the other. My computer has a Gigabyte GA-X58A-UD7 motherboard. They are very large and will only fit into 4 cases. My selection was of course the Lian-Li PC-8N, but make sure you do your homework if you are building a computer by sourcing individual items.

  • I’ve built almost all of my many PC’s, since I realised just how overpriced they are to buy ready built! Saved heaps of money, learned a hell of a lot about them, and I’m not locked into the same setup till the warranty runs out to update!
    Asus Rampage III Gene, Radeon 5870, 8gig 1600 DDR3, Dell 24″ monitor, sweeeet!!! #)

  • With power supplies, I’m pretty sure you’d want a higher wattage (power capacity) for a more powerful machine, rather than a ‘higher voltage’ 😉 Just a typo, I know…

  • I haven’t built a PC for myself in since probably about 2003-4 – though I have built a PC for someone else, and serviced/upgraded a couple of my machines since then.

    As far as my actual desktop PC’s are concerned – my old primary PC was superceded by laptops, and (after having a RAID card addded and 4 HDDs dumped into it) relegated to media server duties, and another was beefed up with RAM to the gills and a beefy video card and turned into a media centre.

  • Oh, and before anyone points it out – yes I’m well aware that aged hardware and PSU’s consume more power than their more contemporary counterparts (even if due to capacitor aging alone) – but until somebody can give me concrete evidence that the cost of buying new hardware will be less than the additional juice my 6-8 year old PCs do, I’ll keep running these till they die.

  • Bear in mind that most no-name computer stores will assemble a PC from your selection of parts for a nominal cost ($50-100), and will also give you a parts and labour warranty.

    They will also hopefully point out where your selection of components is not optimal or could be better utilised, so it’s definitely worth talking to them about your requirements!

  • The PC cycle (mainly RAM, CPU and GPU) has slowed in recent years, so you don’t really need to upgrade as often as in the mid 90s.

    Regardless of whether you build your own or buy something off the shelf, one thing I’ve noticed in recent years is the need for USB slots. USB is used for almost everything now, so make sure what you’re buying (motherboard and case) provides for this and includes USB 3.0.

  • Are there any online stores that allow you to configure a pc, but then send you the individual components to put together yourself. This would seem like a good way to get introduced to pc building.

  • Has anybody looked at the functionality of using 12 volt power supply for a desktop computer rather than 240V

Show more comments

Comments are closed.

Log in to comment on this story!