How to build a computer yourself

I like to build my own computers. There are two reasons you should consider doing the same; controlling quality  and balancing performance. It may seem daunting but it's not as hard as you might think. If you're the sort of person who's willing to pop the bonnet of your car, or you don't mind grabbing a screwdriver to fix something yourself, this is probably within your ability once you know what to buy and how to put it together.

Benefits of building a computer yourself

  • It's fun, really. Half the experience of building a computer yourself is the research you put in before you do it. Find out about what delivers the performance you want for the best price. Good review websites include Anandtech, Tom's Hardware, PC Perspective and Tweaktown. The assembly usually goes smoothly but even if it doesn't, the ultimate outcome is always rewarding.
  • Quality control. It may be possible to buy a computer cheaper than you can build one yourself, but compromises have been made and you don't know what they were. Cheap components are far more likely to fail. You will be living with the PC you build for a while, and nothing is more frustrating than a computer that misbehaves. Building it yourself means you can make the decision about what quality you choose, including to where to skimp.
  • Balancing performance. Buying a pre-built computer means that you need to fit in with the manufacturer’s idea of what you want, not something built just for you. Compromises get made to balance performance for 'gamers', 'video' or 'business'. Maybe you'd prefer to buy a slightly smaller hard drive but faster processor? Doing it yourself means you'll get the best bang for buck.
  • Fixing it is easier. Does fixing a computer make your blood run cold? Don't panic. Computers I have built tend to be more reliable because I build for quality and durability. But even the best systems can fail. Knowing what's in it makes it simpler for you to fix it. If you made some compromises on quality, it will also give you a good head start on where you might need to start trouble shooting. I'll cover some ideas on how to troubleshoot below.
  • Warranty and upgrade. If you think that buying a pre-built system is better because it offers you a warranty, it also comes with a price. You probably cannot open the case for the duration of your warranty without voiding your warranty. Will you really be able to run your computer for the next year or two without any kind of upgrade? You're going to have to return to base for that and pay accordingly. If you build your own computer, and need to add some more memory (a very simple task) you can do it yourself for the cost of the memory. Even better, most parts come with warranty, so you can upgrade your own computer, and still claim parts warranty.

Choosing the right parts

You're not really going to be building a computer, you're going to be assembling one. Think of it a bit like Lego, because it's modular and goes together in a fairly fixed way. You just need to take care to ensure that you choose parts that are compatible with each other. For example, the heart of your computer is the CPU, from which other decisions flow. If you choose a certain CPU type, that will impact what other parts you can buy that will work with it. It may seem incomprehensible at first but really it's not, it just needs some care, and if you're not sure what goes with what, I'll detail below a list of components I am buying for my next computer build.

What parts do you need to build a computer?

  • Case. This is the box it all sits in. You can spend very little money on a case, or a great deal. The difference in price will generally reflect a difference in quality, or form factor. Better cases will come with dust filters, thumbscrews case fasteners, easy to access drive bays and so on. A cheap case is fine but after you've built a few computers, you'll probably find yourself wanting to spend a few more dollars on features you want. Also, it may seem counterintuitive but the more expensive the case, the less likely it is to include a power supply. I'll explain below why that's a good thing. If you want to build a home theatre PC, you can also choose small form factor cases like Shuttle. My current favourite case is the Cooler Master HAF912. It is big, has great internal access, 2.5 inch drive mounts (for SSD hard drives), front USB and audio connections and excellent airflow.
  • Power (PSU). This is often the least understood part of a computer. Everything your computer does relies an a supply of clean, pure power. If you got a cheap case with a cheap power supply, take it out and put it in a cupboard for emergency use only. I strongly recommend buying a good quality power supply with an '80Plus' efficiency rating. 75% of computer failure I have experienced has been power related. Spend money here. You will be able to tell by the weight difference of a good quality power supply and the one you took out of your cheap case, something isn't right. Don't expect a cheap power supply to last, and do expect lots of frustration with a frequently crashing computer if you ignore this warning. Power supplies (also known as PSU's) have a rating to deliver a certain amount of power. Unless you have special needs and will be running a dual graphics card setup, it's unlikely you'll need more than 800 watts. I invest a bit more here than most people and prefer the Cooler Master Silent Pro Gold 800W. I suspect I have fewer PC problems than most people.
  • Processor (CPU). There are two key brands, Intel and AMD. There are plenty of comparisons at the review sites. My preference right now is Intel. The current generation of i3, i5 and i7 chips are nicknamed "Sandy Bridge". They are about to be replaced by "Ivy Bridge" chips with the same i3, i5 and i7 naming convention, so it would be easy to get confused which is which. Both of these models use the same socket system called 1155 (presumably because there are 1155 pins in the socket). The more important thing to remember is that i3 = good, i5 = better and i7 = best. For people building their own system, an i5 or i7 is likely to be the choice. There's an additional consideration too, some of the i5 and i7 models have a "K" at the end of the model number which means it's a more expensive chip that has been 'unlocked' by Intel to allow us to 'overclock' the chip, making it run faster. For first time builds, steer clear of overclocking but if it interests you as a potential future interest, buy the K model chip. I am still tossing up whether to buy the Ivy Bridge i5 3570K or i7 3770K processor for my new PC when they are released.
  • Motherboard. This is as important as the CPU itself. The motherboard actually contains many of the features your computer will have. It will determine what you can plug into it, what type of audio and video you can have, how many hard drives you can connect and so forth. Your motherboard will need the same 'socket' type as your CPU. For current model Intel processors that will be the Intel Socket 1155. Check your motherboard has the same socket type as your chosen CPU before you buy it. Knowing which motherboard to buy is going to take some research but I'd generally advise sticking with one of the 'main' brands, Gigabyte or ASUS. Intel also makes motherboards but I've never bought one as the features offered by Gigabyte and ASUS have been superior when I've been looking. That's the case again this time, I'll be buying a Gigabyte GA-Z77X-UD5H but the GA-Z77X-UD3H is worth considering. I'm buying the UD5H because it has a Firewire (IEEE 1394) connection for my video camera. Otherwise I'd have picked the UD3H because it's a lot cheaper but still high quality.
  • Graphics Card (GPU). Newer processors come with inbuilt graphics that can cope with most PC tasks and games. But if you expect to be playing the latest games at the highest quality settings, you will need a dedicated graphics card. My advice is look to the $200-$300 price range at the time you build. This is often where you'll get a decent improvement from inbuilt graphics but not be paying for the top performance. That said, if you live for games, it's another great reason to build your own PC, because you really can go to town, putting in two cards for maximum performance and focussing as much money as you want on what's important to you. I'm saving some cash here and using inbuilt graphics.
  • Memory (RAM). The current memory standard is DDR3. It's hard to go wrong with memory. Memory has a range of measures for speed but the important one is what speed your processor and motherboard talk to the memory, this will probably be 1333Mhz or 1600Mhz. You can mix and match a bit here. Even if your processor expects 1600Mhz RAM, you should find that 1333Mhz will work. It wont give you the best results you could get, but it should work. The thing to keep an eye out for here is CPU, motherboard and memory all need the same speed capability. If your CPU and Memory are both rated for 1600Mhz but your motherboard is only rated to 1333Mhz, that's the speed your memory will work at. I'll be buying at least 8Gb of Corsair Vengeance 1600Mhz memory. There are other figures you'll see with memory referred to as timing, but unless you're overclocking, just focus on the interface speed of the RAM. 8Gb should be plenty of memory for most people, but there are cases more can be useful. More can be a waste of money though, especially if you install a 32bit version of Windows, which will be able to use less than 4Gb of RAM. So be sure to install 64bit Windows with more memory.
  • Heatsink. This is an optional purchase. Retail boxed versions of CPU's always come with a heatsink and fan combo from the manufacturer. This will be fine if you don't plan on overclocking, which I don't. However, I don't have air conditioning where I use my PC's. It can get very hot in summer, so I like to ensure my system has better than standard cooling in place for the processor. Processors will slow themselves down if they get too hot, and dust collecting on the heatsink will reduce efficiency, so apart from cleaning it at least once a year, having a bigger, better heatsink may be a good idea if your PC is used in a room that regularly gets above 35C in summer. I am buying the Noctua NH-C12P SE14, which is big, efficient, and quiet. It was originally designed for socket 1156 boards but is compatible with newer 1155 socket motherboards.
  • Hard Drive (HDD/SSD). Things have become interesting in the last year with hard disks. New solid state drives (SSD's) have become faster, bigger, more reliable and cheaper but they still cannot match traditional hard disk drives (HDD's) with spinning disks for capacity and price. That said, once you've used an SSD, you will never want to go back because the boost in performance is amazing. This is a key area that being able to balance your system for your own needs will be a major benefit of building your own system. My typical balance is to have a 120GB SSD for Windows and my programs, with all my data stored on a traditional 2TB drive. Motherboards such as the one I'm buying also offer a hybrid option of mounting a smaller 60GB SSD as a cache drive, speeding up access to the HDD by storing data that gets used repeatedly on the faster SSD. It looks to Windows as though you only have one drive, but allows you to buy a comparatively cheaper SSD and get a speed boost. The floods in Thailand raised HDD prices because components for drives were made in the flood affected areas, which helped to push SSD's into mainstream use. I will be buying an Intel 520 120GB SSD for my main system drive. I will probably buy an additional HDD, but for now I have enough storage on my home network, I do not need a traditional HDD for my next PC.
  • Optical drive (DVD/Blu-ray). This is optional. A few years ago it was essential to get an optical drive but I no longer think this is true because most software can be downloaded or loaded from USB. For convenience it's probably worth it, as some software may only be available on DVD, so it is likely I will get a cheaper unit such as the LG CH12LS28 12x Blu-Ray DVD combo drive. I am not locked in on this however.
  • Peripherals. You should be able to re-use your keyboard and monitor. If you need new ones, it's a matter of personal preference. I'll be upgrading my keyboard to a more expensive model with mechanical switches and LED lighting (for use in the dark). I have 2 LED monitors mounted on a dual monitor arm to keep them up off my desk.
  • That's it!

Putting it together

When you look at what you have, you may get nervous but you've already done half the hard work. By choosing the right components that are compatible with each other, you're ready to assemble them. The instructions below are a good checklist for assembling your PC but they are no replacement for the instructions that come with the components. Be sure to read them carefully. The most important is the motherboard manual but even the case will have an instruction sheet, telling you what wires connect to what buttons and how to mount the motherboard to which screw holes. It's all there. If in doubt, Google and YouTube are your friends. Search for instructions or videos on any of the steps below and you should find more detailed help.

Here's a walk through of the steps you'll take to assemble the computer;

  1. Get your tools. At a bare minimum you'll need a Phillips head screwdriver but it's a good idea to have some needle nose pliers or tweezers handy in case you drop a screw somewhere awkward. Some people will say you need an anti-static wrist strap so you don't zap your chips with static electricity. As long as you take basic precautions to ground yourself (don't assemble your PC wearing socks on carpet) you should be okay. Touching the case of a PC that is plugged into a wall outlet should do the trick.

  2. Get the case ready. Get it out of the box it came in and take off both sides. There are probably a bunch of screws, some cabling and a slip of paper with instructions. Read it. You'll see some of the 'screws' are actually special hexagonal 'risers' that screw into the case on one side and have a screw hole on the other. These need to go into the holes on the motherboard tray that match up the holes that will be on the motherboard you bought. These are all standardised. If you're not sure what size your motherboard is, look on the motherboard box. It'll say. If it doesn't, it's 90% likely you have an "ATX" sized motherboard. Put the risers (which are often brass) into the holes that match the ATX layout. It should be on your case instructions. If not, your final resort is simply to get the motherboard out and match up the mounting holes. At this point, it's a good idea to read the manual that came with the motherboard.

  3. Put in the backing plate. If you've noticed the back of any computer has a bunch of connections for USB ports, network and such, it's no accident the case has holes exactly to fit them all. That backing plate is supplied with the motherboard. You'll see a large hole in your case, get the backing plate out of the motherboard box and pop it in the hole, taking note to get the orientation right. If in doubt, match up how the motherboard sits in the case, just to be sure you don't put the backing plate in upside down. I've known one or two to require a bit of pressure to get them in but it's fairly flimsy metal so apply pressure at the edges to pop it in.

  4. Mount the motherboard. You will need to line up the mounting screw holes with the risers you put in the case. if they don't line up, or one is missing, this is the right time to be correcting that. You want all the holes to line up with a riser if possible so that flexing the motherboard is minimised when you put things in. There should be a bunch of small screws that will secure the motherboard that came in the box. Try not to drop these onto the motherboard as you screw it in. This is where you can damage the circuit board if you scratch it. A magnetic screwdriver is handy to help here but I try to place the screw by hand, then align and fix it so I minimise drops.

  5. Case connectors. While there is clear space on the motherboard, I like to connect the case cables to the corresponding pins on the motherboard. The manual will explain which is which. This is what makes the power and reset buttons work, gives you the power and HDD lights on the case, USB connections and more. If they don't work, you may have reversed the polarity of the pins (plugged it in the wrong way around). It's also a good time to plug in the case fans to the fan headers (pins) on the motherboard. Do not connect a case fan to the header marked "CPU Fan" though.

  6. Insert the power supply (PSU). The case will have a fixed position for the power supply. Depending on the case, the power supply fan should either pull air from inside the case, or outside. Just be sure not to put the power supply fan against the steel edge of the case. This will guarantee PC failure at some point. On more recent cases, the power supply is usually at the bottom, with air intake from outside the case, pulling fresh outside air directly into the power supply rather than pulling in already hot air from inside the case. If you have this type of case, don't put it directly on carpet, elevate the PC on a wooden board, books, anything. Securing the PSU is fairly simple, it can only go in one place, and only has a few screws. Focus here, PSU's are heavy. Forgetting to screw it in securely will cause a problem when you move your PC and it falls out of place, destroying the interior of your computer.

  7. Arrange the power cables. Better cases have holes and routing for keeping cables neat and tidy. Now's a good time to arrange the power cables to they are the least obtrusive. I also plug the motherboard power in at this stage. The manual will explain where the power connectors are on your motherboard but there will be at minimum one, a long double row connector that directly fits into a socket on the motherboard. Take note of the clip on one side, it aligns with a small notch 'lock' on the socket. There will probably be another small power connector on the board as well, connect this too.

  8. Insert the CPU. Your processor should be in a retail box with a stock cooler/fan (heatsink). For now we're just putting the processor in the processor socket. Read the instructions that come with the processor and read the motherboard manual page for this. The processor will only go in properly one way, with fairly clear instructions on correct alignment. You'll need to clear the motherboard socket first, by lifting the lever next to the socket. It's a press/release spring type lever, so you need to push it down, move it sideways and pull it up. Take out the plastic lug that was in the socket to protect it, then insert the CPU as per instructions. At this point we are NOT going to put the heatsink on.

  9. Insert the memory. Again, read the motherboard manual and any instructions that came with the RAM. Memory is pretty simple to insert. Just by looking at it you'll see there are a long line of pin connectors, and a notch. Align the notch in the RAM with the notch in the socket and you'll have the alignment correct. The memory sockets on the motherboard have small push levers at each end. Push these outward so the socket is 'open'. Gently place the RAM module directly down into the socket. The edges of the RAM modules should be sliding into the edges of the push levers and the notch in the memory should align with the notch in the socket. As you push down with increasing force, the levers will pull inwards and should lock into place. There may be a click, maybe not, but if the levers don’t come back in all the way, you haven't pushed the memory into the slot properly. it may take a little more force that you're comfortable with. Don't push with all your might, but be insistent to get it into place. Securing the memory properly is important. If you have less memory modules than there are slots on the motherboard, great, you can add more memory later. I'd recommend putting the first memory in the slots closest to the CPU as these will be the most difficult to access later. Which is why we don't have the heatsink in place yet...

  10. Mounting the heatsink. If you are using the stock cooler supplied with the CPU, this will be a fairly simple process. The instructions in the CPU box should fairly clearly show how to do it. You'll need to align the four push pins around the heatsink with the four holes around the CPU socket. Take note of where the little cable for the fan is relative to the pins on the motherboard you need to connect it to. More than once I've had to take a heatsink off and reorient it so the cable would reach the pins. If you've bought a different heatsink, it should come with detailed mounting instructions which may include a back plate on the other side of the motherboard. This is why we took both panels off the case. If you bought a cheap case though, the motherboard tray may not allow access to the rear of the motherboard, in which case, you'd need to insert the CPU and mount the heatsink BEFORE you put the motherboard in your case. The stock cooler will come with pre-applied thermal paste to improve heat conductivity between the cooler and CPU. If you add your own heatsink or remove the original one, you will need to apply thermal compound. I'd suggest a few YouTube tutorials for this, but a small blob, the size of a pea or slightly less is the right amount, on the CPU, right in the middle. Less is more. Too much and you risk the thermal compound insulating rather than conducting the heat.

  11. Adding the GPU. If you want to play games and have bought yourself a graphics card, this will go into one of the expansion slots on the motherboard. Again, read the manuals. In the motherboard manual you will be looking for the slot that they recommend you insert a graphics card. Some motherboards have the same size slots but they are not all 'equal'. So it pays to be sure you put it in one with no limitations. All things being equal, I like to place GPU cards toward the 'top' of the case. You may need to plug a power connector in to the GPU. Check your manual.

  12. Mount your drives. Newer cases tend to have a fan at the lower front of the case. If you have drive mounts behind this fan for 3 1/2 inch drives, place them here so they get good airflow. If you have a solid state drive (SSD) you may need a 2 1/2 inch adaptor if your case doesn't have the correct size mount. The case I mentioned above does have 2 1/2 inch mountings and I expect all new cases will too, but many existing and cheaper cases do not. So be sure your SSD comes with an adaptor or you'll need to buy one. Screwing drives in is fairly straight forward. Be sure to secure them well so there is no movement possible inside the case. The drives will connect to the motherboard with SATA cables that should have been supplied in the motherboard box. We are on the cusp of changes in SATA technology, so if your hard drive is capable of SATA3, also known as SATA6Gbps be sure to plug it into the SATA3/6Gbps socket on the motherboard. If you plug it into one of the older SATA2/3Gbps sockets, you will not get maximum speed. It's unfortunate that SATA3 and SATA3Gbps can be confusing but if you're careful, and just remember to buy a SATA6Gbps SSD and plug it into the SATA6Gbps socket on the motherboard, which will be clearly shown in the manual, you are fine. Spinning hard disks struggle to use the power of the new SATA connection, so can mostly be used on SATA2/3Gbps connectors with no loss of performance. When mounting your optical drive, you will probably need to remove one of the cover plates on the front of the case. Your case manual should explain this and drive mounting.

  13. Time to POST. We're not sending mail, POST means Power On Self Test. Leaving the sides off your case, plug it in to power, monitor and keyboard. Then switch it on. You should hear a beep (if you connected the case speaker) and see some text or a big logo appear on screen. That's good, it means you have assembled the PC correctly. If you don't see anything, or there are alarming beeps it's time to troubleshoot (see below).

  14. BIOS settings. Assuming all went well and you got the computer to POST it's time to head into the BIOS (see the manual) and change the settings to suit you. The manual is your friend here. If uncertain, date and time should be enough, but you may need to go into the menu that sets the boot sequence for your drives. 

  15. Install Windows. You may need to set your optical drive to be first in the boot sequence so you can then insert your Windows (or Linux) DVD and start your operating system installation. You'll want to come back later and set your hard drive to be the first boot disk unless you think you may wish to boot from DVD in future. At this stage, you're done. You've built the PC and you're installing your software.

What if it goes wrong?

Doing yourself is rewarding but does carry some risks. If you break something along the way, or it just doesn't go as planned, it can become highly frustrating. You don't have anyone else to point at and say "fix it". If you're not sure what may be wrong, it can also be somewhat depressing as you sit looking at an investment that wont even blink back at you. What I can say though, is that for all the times things have gone wrong, and I have had a few, simple perseverance, retracing my steps and the logical way things should work has seen me ultimately successful.

Although you may be concerned about the risks of building a PC and not having anyone to turn to, the reality is different. I prefer to build my own computer because I prefer to fix it. Not that much really goes wrong with PC's. Mostly it's power supply that leads to a 'dead' computer. Being able to swap a PSU yourself means that when you have a dead computer, you're 30 mins away from a working computer. Because you built it, you can fix it. The other most unreliable part of a computer is the hard drive, but that's easy to spot and just as easy to fix by plugging in a new one. Why pay a technician to do those things for you? It's much cheaper to buy the spares and just do it yourself. 

Troubleshooting

  1. Read the manual. If something isn't working, chances are it's because you've missed something. I've had very few systems dead on arrival. Go back step by step and ensure you've plugged all the cables into the right sockets, the memory is inserted properly, and if you're getting a strange series of beeps at POST, see what the manual says about that. They usually have a meaning that's explained.

  2. Check the power. We've all done it. I know I have. My best effort was 45 minutes until it occurred to me to check that the computer was actually plugged in and turned on. It wasn't. Problem solved.

  3. Check the power supply. Most of the problems I've had with computers have been power related. If you get nothing at all from the computer, no response, it's probably power or the power supply. If you bought a cheap case and kept the cheap PSU in a cupboard as a spare, put it to some use by swapping it to see if you can POST. If you didn't swap it out for a better one, the problem is almost certainly the cheap PSU you got with the case. If there's one spare I would advise you keep in a cupboard, it's a replacement PSU.

  4. Google is your friend. If you are having problems that none of the above help with, it's time to search Google. Every problem you could have, someone else has had. Find the answer, it's waiting for you. 

  5. YouTube is your friend. Sometimes you need to see how to do something. YouTube has all sorts of info on things from inserting memory and CPU's to mounting heatsinks and applying thermal paste. Check it out.

  6. It's probably power. Seriously. If the PC just stops working, it's almost always power. 

  7. It's not power. If you've swapped out the PSU and still don't have a working PC, it may be the motherboard. More specifically the power system on the motherboard. Unfortunately that means replacing the motherboard. I don't generally suggest keeping a spare for that but it's still cheaper than paying a technician. If that doesn't work, see Google above or find a friend.

  8. When all else fails. If you've tried everything, rebuilt half the computer and it still doesn't work, you are suffering extreme bad luck. If at wits end, it may be time to get professional help.