This is in no way a full list of stuff to have in mind when buying parts for your first pc. Use it in conjunction with something else. I just wrote down everything thats came to mind that good to take into consideration. Use it at you own risk. There is most likely a lot of errors in it. Actually, if you find something thats correct it must be because someone else has rectifyed it and told me.
Chassis
- Does it support your motherboard? (micro-ATX, ATX, extended-ATX?). Also, you don't want a huge midtower chassis that supports every card if your going to choose a micro-ATX mainboard.
- See if your chassis come equipped with a PSU (power supply) (most (better) chassis' don't, so that you can choose yourself)
- Consider the fans equipped in the chassis.
- Are there enough fans for a good air-flow? Or do you need to buy extra fans?
- Over time, dust will accumulate inside (which is bad for several reasons), so you should clean the inside of you computer from time to time (eg. with a can of compressed air).
- Dustfilters behind intake-fans reduce the dust-intake
- Exhaust fans are great at maintaining a good airflow, but they suck air (and dust) in from every hole in the chassis. A few chassis' come equipped with dustfilters to cover these holes
- Consider the noise-level of the fans - especially if you're used to a silent system (a laptop maybe?). During idle, they could be the main source of noise from your PC
- Be sure to do some good cable-management with your system (I'll improve air-flow!). Some chassis' have features for cable-management (eg. removable backplate)
- Make sure your chassis has the number of external ports you need (eg USB- and audio-port), and that they a located where you want them (on the top? On the front?)
- Beware that long graphics card cannot fit in all chassis'
- Lastly, of course, choose one that you think look nice
PSU
- First of all, be sure to choose a good-brand PSU. There's a lot of bad manifactures out there that make PSU's that power what it's supposed to power. This is very important - Do not save money by buying a cheap PSU!
- Choose a PSU with enough wattage. The graphics card is probably goint to use the most power. The specifications of many graphics cards says what wattage is needed (for the whole system)
- Also note how much ampere the PSU can deliver from the 12v-rail. Look up your graphics card specification again to see its requirement on the 12v-rail
CPU
- See if your CPU comes with a fan to it. (it most likely do)
Mainboard
- As described above, make sure your chassis supports the mainbords formfactor (micro-ATX, ATX, ...)
- Choose a Mainboard that has a socket that supports your CPU - if not, your CPU won't fit.
- Take a quick look at the chipsets on various mainboards. Some allow overclocking, some doesn't
- If you plan on installing more than one ghraphics card, make sure that the mainboard supports it (SLI/crossfire)
RAM
- Your RAM modules must physically fit in the mainboard. Eg. when choosing DIMM 240-PIN RAM, your mainboard should have DIMM 240-PIN RAM sockets. Also (of course) make sure your mainboard has enough slots for RAM.
- Note if your mainboard supports single-, double, and/or triple-channel mode. If your mainboard is using dual-channel, you should install RAM-sticks two at at time! If it is triple-channel you should install RAM-sticks three at a time! It's no good installing three sticks of RAM on a mainboard with the dual-channel mode. Worst case is that you can't use the last stick of RAM until one more stick is installed
- Make sure your mainboard support DDR3 ram if you choose DDR3 ram, or another RAM-technology if you choose another RAM-technology
- consider the speed of the RAM's (eg. 1333MHZ, 1600MHZ, ...). Your mainboard should support this as well.
- Also consider the CAS Latency (here lower is better)
- Windows 32 bit can't use more than (at most) 3.2GB of RAM. Choose the 64 bit-version if you want more RAM than that. Your Mainboard and CPU must also support 64 bit then.
Hard drive and Optical drive
- Make sure your motherboard supports them (eg has free SATA-ports if required)
- Consider an extra SSD disk for the operating system
- Noise might be an issue for some devices
Graphics card
- Look at NVidia's features (3D Vision and more) vs ATI's features (eyefinity and more) and figure out whats most important to you.
- Read reviews online before choosing. It's hard to say how good a card is from its specs alone. Also note the cards temperature and noise level (idle and load). The graphics card could become the loudest component of you PC (under load).
- Take a look at the cards directX-level. It's a good idea to choose a card with the highest directX-level available
- More RAM on the graphics card is required when gaming at higher resolutions. (Bear in mind that (some) dual-GPU cards (or cards in SLI/crossfire) can't share the RAM between the GPU's effectively. Instead each GPU has to store everything in their 'part' of the RAM, so everything is stored twice.)
- Beware of microstutter if you're choosing a dual GPU card (or GPUs in SLI/crossfire)
Operating System
- If you choose windows, OEM licenses are cheapest, but they bind to the hardware