Your computer requires the following minimum components:
Motherboard
CPU
RAM
Graphics card(s)
Hard Drive
DVD-ROM
Power supply
Case
Selecting the CPU and Motherboard
Generally you start off deciding which processor you want. Note the manufacturer, model, and "socket" style. The socket style might be a name, or a pin count, or a combination. Next, you'll select your motherboard. Motherboards include a CPU socket, and will only support a narrow range of CPUs. Use you CPU model and socket style and match it to what the motherboard supports. Sometimes a CPU will come with a cooler - if it says "OEM" or "BULK" packaged, it generally doesn't. If it's a "BOXED" intel, though, it might. Most serious computer builders buy a fan anyway, and throw the stock one away. Look for a fan that matches the socket style. The fan will probably come with heatsink grease. You can use it, or buy something separate. At the high end (125W processors, for instance) you should consider this more carefully, but for most people the stuff that comes with the processor or fan will suffice when applied correctly.
Motherboards also determine the memory and graphics card you can use. Once you choose the CPU, you'll have a variety of motherboards you can choose from. Make sure the one you choose supports the graphics card and memory you'd like to use
Selecting the Memory
Check out the motherboard specs for memory (also called RAM) support. You'll want to know the type of memory, the socket style, and the speed. Types are similar to "DDR2" and "DDR3" these days. Older computers might have DDR SDRAM, or just plain SDRAM. Socket style is usually a number referring to the number of contacts between the memory and the motherboard. Common sockets for desktop memory are 168, 184, and 240. Memory speeds are a little confusing because there are two ways to talk about speed. Many places you'll see both methods, but in some cases you'll only see one or the other. For instance, DDR3 1600 is the same as PC3 12800. DDR2 800 is PC2 6400. Your motherboard will support a specific type of memory, a socket style, and will run up to a certain maximum speed.
- A single memory is usually referred to as a stick of memory. Most motherboards have 2 to 4 sockets for memory sticks.
- The type (DDR, DDR2, DDR3) has to match the motherboard's supported type EXACTLY. You can't put DDR3 into a DDR2 socket, even if the socket styles match.
- The socket style (168, 184, 240) has to match the motherboard support type EXACTLY. You can't put a 184 memory into a 240 socket.
- The motherboard will support a range of memory speeds. You can almost always put in slower memory than your motherboard supports - the memory tells the motherboard what speed it is and the motherboard adapts. You can't always put in faster memory (you should be able to, in theory, but I've seen too many failures to trust this). Try to stick with memory at speeds the motherboard supports.
- Most motherboards support dual channel or triple channel memory. If you put two or four of the exact same memory (type, style, speed, size) into a dual channel motherboard you will increase the memory performance of the computer - it gangs them together and accesses them simultaneously in a very sexy way. For triple channel memory you need three matching sticks (type, socket style, speed, and size).
- Dual or triple channel depends on the motherboard - there's no "special" dual or triple channel memory sticks - just type, socket style, speed, and memory size.
- Check the motherboard manual for dual channel and triple channel support - usually you have to use specific memory sockets on the motherboard to get the full effect.
- Motherboards typically support a maximum size for each stick of memory. If you put an 8GB memory sticks into one of the memory slots and the motherboard only supports 4GB memory sticks, then chances are good it will only use 4GB of that memory - the rest is wasted.
- You can mix and match memory sizes, and often memory speed (though I don't recommend mixing speeds - it should work fine, sometimes it doesn't, and the infrequent computer crashes are frustrating since you can't easily figure out why). The memory bus will run at the speed of the slowest memory you have in there. It will add together all the memory you've added up to the maximum the motherboard supports. So if you want, you can start with two 2GB memory sticks, then add a 4GB later, then another 4GB later. This complicates dual and triple channel memory setups, though, so for beginners just get two or three of exactly the same memory if you want the best performance and you have modest memory needs.
There is more to memory than the above (such as timing), but again, this guide is meant to get you up and running for your first simple build, and as you do it you'll learn the additional stuff. Your next build will be better. If you really want to have the "ideal" first build, pick everything you want, then pass it by an expert and ask for their opinion. Do this a few times and you'll pick up the latest and greatest tips and tricks.
Selecting the Graphics Card(s)
New motherboards support "PCI Express" for graphics cards. Sometimes termed PCIE or PCI-E or similar. Do not confuse these with regular PCI cards or slots. The last generation of video slots on the motherboard were referred to as AGP. Each PCIE connection of the motherboard is called a slot, and supports several "lanes" of communication. Most motherboards come with at least one PCIE slot that can support x16, which is 16 lanes of communication. They often include a few more PCIE slots, but they might only support x2, or two lanes of communications. Motherboards that are meant for dual video cards - termed SLI - have two x16 PCIE slots. You don't have to install two video cards, even if you have a motherboard that supports SLI, but you can't expect to install two video cards into a motherboard that doesn't support SLI and get the huge increase the video cards advertise in an SLI configuration. If you want SLI generally you should get two of the exact same video cards.
You can install multiple video cards into one computer, and hook up many screens. SLI is meant to increase video performance to one screen. If you want multiple monitors and aren't a heavy gamer, there's no need to mess with SLI. Most video cards support two monitors. If you want three or more, you might need more than one video card.
The video card might require a connection directly to the power supply. Make sure you select a power supply that has this connection.
Selecting the Hard Drive
Most new hard drives are simply plug and play into most new motherboards. You really don't have to worry about whether the size, speed, etc matches anything on your motherboard. Most drives are SATA, and most motherboards support SATA. Older computers might use ATA/IDE (two names for essentially the same thing) and you can still buy IDE/ATA drives, but SATA is the standard now.
You do have options, though, and if you'd like to understand them, read on.
- SATA, SATA2, and SATA3 all use the same cables and communications and can be mixed and matched willy-nilly. You can put a SATA3 drive on a SATA2 motherboard, and it will run just fine. You can put a SATA2 drive on a SATA3 motherboard and bob's your uncle. SATA3 is faster than SATA2 which is faster than SATA. You'll also SATA speed rather than SATA number - SATA 1.5Gb/s is SATA1, SATA 3.0Gb/s is SATA2, and SATA3 is SATA 6.0Gb/s. Most resources will refer to the speed (1.5, 3.0, and 6.0) rather than the sata number. Don't get confused - SATA3 (also seen as SATA III) is not the same as SATA 3.0. When in doubt, look for speed in Gb/s (gigabits per second) rather than the version number.
- SSD - Solid State Disks (or drives) are flash drives that connect like SATA hard drives. They are generally faster than regular hard drives, and quite a bit more expensive. Use them if you want much higher performance and have the cash for it.
- You can mix and match drives. Your motherboard typically supports 4 or more SATA hard drives. Many people use SSD drives for their operating system and game files, and then a slower regular SATA drive for their documents, videos, and other large, but not frequently accessed data.
- Hard drives have a speed that refers to how fast the platters are spinning inside. 5400, 7200, and 10000 RPM (also known as 5.4k, 7.2k, and 10k) are the most common varieties. As a general rule, the faster the spin rate, the faster you can get large files on and off the drive. Generally, the faster drives also need more power, run hotter, and are noisier. There are 15k drives, but they are often targeted at enterprise (server farms) use and aren't widely available in SATA.
- If you manage millions of tiny files, seek time is more important than spin rate. A smaller seek time will appear to be faster for a lot of little files than a larger seek time. For most people you won't notice much of a difference.
The hard drive will require a direct connection to the power supply, but all new power supplies include SATA style power connectors, so you don't have to examine the power supply specs for this.
Selecting the DVD Drive
Most operating systems (OS) come on DVDs now. You can load an OS using flash, or even the network, but if you're reading this guide then chances are you'll want to have a DVD drive to avoid frustration. Newer DVD drives use SATA just like the hard drives. Same cables. The drives are slow enough that the SATA speed doesn't matter much, and so you usually won't see anything about which speed or version of SATA a drive uses. Don't worry about it.
DVD drives are the cheapest, but blu-ray drives aren't terribly expensive, and dvd burners and blu-ray burners aren't expensive. But unless you plan on burning blu ray, or watching blur ray movies, you should skip that and simply get a DVD burner. Upgrade to blu-ray when you'll actually use it, as those drives are still getting faster and cheaper.
DVDs and Blu-rays require special software to watch their movies. Some versions of windows came with software built in for DVD viewing, but not all. As far as I know, no version of windows came with Blu-ray software. You can buy DVD and Blu-ray drives with and without software. If you intend to watch movies on your computer, it's cheapest to buy the software with the drive. If the listing doesn't say, "includes software" you should assume it doesn't. In some cases you can buy a blu-ray drive that "includes software" but the software doesn't actually have the blu-ray decoder - just dvd and blu-ray burning software. If in doubt, ask others, or use a drive that specifically includes PowerDVD or Cyberlink, and check out which version of that software it uses. New software is usually about $100, and if you're building a home theater you're probably going to buy it anyway - most drives that do include software are bundled with older versions that might not include the newer high quality audio or 3D bluray functions.
Selecting the Power Supply and Case
Finally! Down to the last two pieces.
The power supply needs to power your whole computer. If you're buying new, cheap stuff, then you can probably get a 500W power supply and call it a day. If in doubt, you can always get a larger supply - your computer will only use as much power as it needs. So even if you only need 300W, you can put a 1200W supply in there and you're done. When in doubt, get a bigger supply. You'll pay more, but it's not going to hurt the computer to go big.
Make sure your chosen power supply has the right connector for the motherboard and graphics card. This is mostly standardized, so if you get a power supply that handles the wattage you need, chances are good you'll end up with the right stuff. However, it's easy to look at the power connector type on the graphics and motherboard, and make sure the power supply includes those two specific connector types.
You can add up all your power requirements - the CPU and graphics card particular will list their power requirements. Factor in another dozen watts for memory, and the DVD drive. The hard drives will generally consume under 20W each. Motherboards use less power than the processor, so if the motherboard doesn't list a recommended power consumption, just double the processor power and it'll give you a good margin.
Add up all the watts and get the next size bigger power supply.
If you're going big, you might have a 350W graphics card, a 125W CPU, and generally if you read the manuals they'll tell you the minimum size power supply to get - mainly because they may consume 350W on average, but sometimes they will spike and consume 2X as much for brief periods of time. So for the above graphics card, it asks for a 700W power supply minimum, even though it also says it only needs 350W on average. When in doubt, follow the guidance in the manuals. For this computer a 700W supply, including the hard drives, DVD, etc, should be fine.
If you're running SLI high end video cards you'll have to start looking at the 1000W (1kW) power supplies and bigger. This is a ton of power, though. The average house outlet only supplies 1800W. If you hook up a high end gaming computer, a few big monitors, your speakers, and a bright room lamp, you might find yourself blowing the fuse once in awhile.
The case holds the stuff so you don't spill coffee on it and ruin it or the cat doesn't rub up against the fans and get turned into kitty fluff blowing out the back of the computer. The only thing you really need to deal with here is:
- Does the case fit your motherboard. Standard motherboards fit standard ATX cases. Mini ATX motherboards fit both ATX cases and mini-ATX cases.
- Get a case that has enough room for your DVD drives and hard drives. If you only have one DVD drive and one hard drive, any case will do. If you're running a server in your basement and need 5 hard drives, you might have to look around a little bit.
- If the case comes with a power supply, it is garbage, treat it as such. I've had OK success with "included" power supplies, actually, but good cases don't come with them, and when cheap cases do you can bet they'd paid as little for the power supply as they thought they could get away with. Plan on buying a power supply, and use this one to bean the neighbor's dog when it bites you. The cables are just long enough to get good swinging leverage and really damage that poor puppy's brainpan.
Whew!
Now for the fun part, which I'm going to quickly gloss over below because you and I both know I'm probably not going to get around to writing a more comprehensive guide.
Assembly
Clear off a table. Yes, you need a whole table - this is your first time, and there are dozens of parts and pieces and little bags. Collect a screw driver (phillips - the one that looks like a cross or plus when viewed head on), a pair of small pliers if you have them, scissors, and a knife. Set all the boxes on one end of the table in a pattern that allows you to open them and leave them open while you work. That way you can leave the parts and screws and bits and pieces in the boxes until you actually use them
There are really only three sizes of screws you'll use on the computer, and two of them are falling out of style. So keep in mind that except for the heatsink attachment you can almost always mix and match screws. You shouldn't need to though - everything that needs screws comes with them.
Static can and will damage your computer. In most homes the humidity is high enough that you don't have to worry about it if you don't want to. If you're walking around zapping door knobs though, ask for the proper way to avoid static in your work area before assembling your computer. There are a number of things you can do without buying anything, and if you can't help it, a simple static wrist band with cord that clips to the computer case is sufficient. But in most environments you can probably perform the following assembly without worrying about it.
When I assemble computers in a humid environment and don't want to use my static mat or wrist band, I take the case out of its bag, set it on the table, and put the motherboard bag with a corner or edge under the case. Touch the case on a metal part each time before you touch the anything else. Most components will come in static bags. Hold the static bag with the component inside, and touch the computer case on a metal part at the same time to you equalize the charges of the parts inside the bag with the parts already on your work surface. It won't really be a fully grounded system, and you really should do more if you are zapping doorknobs or cat noses, but this rudimentary grounded work surface will at least protect your components minimally.
Prepare the case
Take the case out of its box and bag. Open the side and set the case on its side on the table so the open side is straight up. Remove all the bags and such. Remove the power supply if it has one (there are four screws on the back of the computer where it plugs in - remove them) and throw it away. Keep the screws if you like, though your new power supply will come with some as well.
The plastic baggies have an assortment of screws and standoffs. The standoffs look kind of like screws on one end (the screwy part) but then look like hexagon tubes on the other end. Using the motherboard manual as a guide, attach the standoffs to the inside side of the case where the motherboard will sit. Depending on the case and your motherboard you'll need 6-15 standoffs. Install them by hand, then use the pliers to tighten them another 1/4 turn.
There's a large-ish rectangular hole in the back next to the motherboard spot. The motherboard came with a plate that snaps in place into that hole. Take the plate and look at the motherboard connectors. You may need to remove some bits of metal from the plate so the motherboard connectors go through. Some pieces of metal are probably going to remain since these plates are generic, and you may not have some connectors the plates might be used for.
Now take the plate, and put it through the rectangular hole from the inside of the case, with the decals on the plate facing the outside of the computer. It can go in two ways - generally if there's text on it, then with the computer case laying on its side with the open side up, the text will read right side up, or will read right side up if the case is on its feet. Refer to the motherboard manual if it's not clear, and if it's still not clear, set it aside for now and when you install the motherboard it will only go in one way.
There may be wires inside the case that lead to the front panel. Take these wires and lay them up and over the edge of the case so they stay out of the way when you install your motherboard.
Attach the CPU
Take the motherboard out of its bag. Set the anti-static bag it came in and the foam it came in on the table, then put the motherboard on top of the bag/foam. Take the processor out of the box. Do NOT touch the top or bottom of the processor - leave it in the bag until you are completely ready to install it, and only handle it by the edges, You don't want fingerprints on either side of the processor.
Read your CPU manual installation instructions, your motherboard manual CPU installation instructions, and your CPU cooler installation instructions.
You will probably be installing some parts of the cooler first, then the CPU, then the CPU thermal grease, then the CPU cooler. You may have to attach portions of the cooler to the case. If you can, install the CPU and cooler to the motherboard before putting it in the case. If not, simply follow the instructions. Fortunately you threw that terrible power supply away, so you should have a little more room in the case to work.
Each processor socket type has a different method of installing the processor. Use both the motherboard manual and CPU manual to install the processor. You'll probably be pushing a lever down. Make sure the processor is seated correctly and that any hinges go down without difficulty before pushing the lever down. The lever will take a good bit of force to go down, and it will latch once its down.
Each processor socket type has a different method of installing the CPU cooler. Make sure you follow the instructions.
When instructed to put on the thermal paste or grease, put a single drop on the center of the CPU top. Don't try to spread it around, don't make a circle with it. Just a single drop on the center - less than half a pea's worth. Follow the instructions given in the CPU cooler's manual if in doubt.
Install the CPU cooler. Like the processor lever, this make take more force than you are expecting. Go slow, follow the instructions, and it should work out. There is a cable for the CPU fan - attach it to the motherboard on the CPU Fan connector nearby.
If you get stuck or are uncertain, there's a youtube video for nearly every socket type and every cooler type. Watch it and you'll see how your specific configuration is assembled.
Attach the memory
You can attach the memory in the case, but it's easier while you still have the motherboard out. Each memory socket has latches on each end. If they are upright, push them outward to expose the edges of the socket. Look carefully at the socket - you'll see two rows of pins, and at one or two (or three) spots you'll see the pins are interrupted by plastic ridges. Look at the memory sticks - they have slots for each plastic ridge (and perhaps an extra slot, or a wider slot). Match the ridges up with the slots - this is how you know you've got the memory in the right direction.
If you have fewer sticks of memory than sockets on the motherboard, or you want to take advantage of dual or triple channel memory, read the memory installation guide of the motherboard - it'll tell you which slots to use for double and triple channel memory.
Slide the memory into the socket. Do NOT try to latch it with the latches. Keep pushing on the memory stick straight down - make sure you're not at any angle, or you'll slip and flip the motherboard. Push it straight down with the heel of your hand, and you'll feel it click into place. If you watch while it clicks, you'll see the latches pop into place by themselves.
Attach the motherboard
If you didn't install the rectangular case panel that came with your motherboard, now you get to figure out the puzzle. Place the motherboard into the case with the connectors protruding through that rectangle, and the CPU/fan/memory facing up. You should find that all the screw holes in the motherboard have a standoff right below them. If not, take the motherboard back out, and rearrange the standoffs to match. Make sure you don't have any extra standoffs where there aren't any motherboard holes. You'll likely have to deal with special standoffs or screws for the CPU cooler as well.
You can now look at the rectangular hole and see how the motherboard connectors fit, and match up the panel if you didn't snap it into place earlier. Move the motherboard back away from the panel a few inches, and snap the panel into place from the inside of the case.
Place the motherboard back over the standoffs while lining the connectors up with the holes in the panel. Check again to make sure you've uncovered the connectors you plan to use - it might be difficult to do later.
Using the screws that came with the case (or motherboard if it came with some) screw the motherboard onto the standoffs. Put all the screws in loosely first, then tighten them only after they are all in place. Make sure you don't leave any loose screws rattling around in there.
The cables from the front of the case attach to the motherboard. You'll need to use the motherboard manual and case manual or sheet to attach them. At minimum you need to attach the power button - you can leave the rest detached if you like, but you may find the power LED and other features useful as well.
Install the drives
Put the hard drive into the case from the inside. There are spots for it. The case guide may help. Screw the hard drive into place using two screws on each side. You may have to remove the computer's other side panel for this or remove the drive bay. If you have a small case or large motherboard it may seem impossible to get to the other side - usually the drive bay comes out of the case using a screw or two and/or a lever. You can get away with 2 screws, or if the case has a lever to hold the hard drive in place you might no need screws. The more expensive cases often have guides or manuals that help you figure out the best way to attach the drive.
The DVD drive goes in from the front of the case. You may need to remove a large panel to slide it in. It uses different screws than the motherboard, power supply, case, and hard drive, so be sure to use the screws it came with, and not the other screws. Sometimes the case comes with a selection of screws.
Keep in mind - the screws should always start easy, you should never have to force them. If the screw goes in easily, but then becomes hard to turn before it seats against the metal, remove it and use a shorter screw.
Connect the SATA cables between each drive and the motherboard. It usually doesn't matter which connectors on the motherboard you use, but the motherboard manual should help. If it has RAID and regular SATA connectors, skip the RAID connectors and use the others.
Install the graphics card
The graphics card slot(s) (PCIE x16) is usually the slot(s) closest to the CPU. There are covers on the back of the computer case next to each slot which you'll need to remove to expose the graphics card connectors. There's a cover for each slot - just remove the one or two next to the graphics card slots depending on how wide your graphics card is. The slot is actually inbetween these removable panels - you'll want to remove the panel next to the slot that's further from the CPU. It'll become more obvious when you try to fit the graphics card in place. If each cover has a screw, or can be put back into place with a little attachment, you can remove all of them, then put back the open slots later.
Check out the motherboard manual if you aren't sure which slot is the right one for the graphics card.
Remove the graphics card from it's static bag, then slide it into place, lining it up with the slot and the holes you uncovered in the back. Push it down until it clicks into place. Use a screw to fasten the top metal bracket of the video card to the case where it meets the hole on the back of the computer. The case may have a lever or another mechanism to hole the card in place, but sometimes screws are better overall for noise and vibration issues.
If you're doing an SLI installation, follow the manuals for the video cards and motherboard.
Install the power supply
Untangle the wires from the power supply.
The power supply sits against the large almost-rectangular hole in the back of the case. Find the four holes on the power supply, and find the four holes on the case. They are in a specific pattern, so you can't put it in backwards. Line it up, slide into the case, then screw it in place. Lay the wires up and outside the edge of the case so you have a clear view of everything.
Attach at least two power connectors to the motherboard. Older motherboards only had one, but these days very few motherboards only need one connector. One will be the largest, longest connector from the power supply. That usually goes near the processor or memory, towards the front of the case. If it seems shorter than the connector on the motherboard, look for a smaller connector that snaps onto the big one. The power supply manual should help you out with this.
There's another connector just like the big one, but shorter. That goes near the processor. If it's not the right size, look for one that fits from the power supply.
Some high-power motherboards are now including a connector that looks like a hard drive power connector near the graphics card slots. Go ahead and plug in the matching power supply plug if your motherboard needs it - read your motherboard manual if you aren't sure.
There is a connector or two specifically for the graphics card if you have a high end graphics card. Read the graphics card manual if you aren't sure - if it doesn't have a connector, it doesn't need it, but if it does have a connector, you have to connect it. The connector on the power supply matches the one on the graphics card, or there's a cable in the graphics card box that will adapt it for you. Connect it now.
The hard drive and DVD drive both use the same type of power cable - connect them both now.
You're done! Wooo!
You can hook up a keyboard and monitor to make sure it boots up prior to putting the case back together. It should go to a BIOS screen, and will probably tell you your memory, and a little about your hard drives, and eventually your graphics card. Then it'll complain about not having an operating system or bootable media.
I'll leave that part up to you. Hint: It puts the windows/linux DVD in it's DVD drive, or it gets the hose again.