Make sure the computer power supply will fit the case that you have
You must absolutely make sure you know the type of computer case you have before you go out and buy a computer power supply. The standard is ATX but there are also micro cases out there. Make sure the computer power supply will fit your case. If in doubt check you computers manufacturer page, or, failing that sometimes you can see the power supply label from the back of the PC and google that. When all else fails you'll need to open the case and look for the label. If you have a normal size PC the standard is ATX.
What power output should the computer power supply have?
Most people think getting the most powerful computer power supply is the way to go, but usually this isn't the case. Getting an overpowered power supply for your needs means spending more money on electric and more heat inside the case, a no no for you gamers out there. Most inexperienced computer power supply buyers just look at the power output, but not the quality of the power output. We'll cover power quality later.
If your previous power supply worked well then you can simply get one in that power range. Keep in mind if you're upgrading your video card you'll need to account for this.
If you're building your own PC then simply add up the power requirements of all your components, add 10% or so, and go with that size computer power supply.
Make sure you get a computer power supply with enough connectors
Not every power supply has the same number of connectors (cables). This may be especially important to you if you have multiple hard drives or even multiple video cards and need more power connections to account for them. Now, for hard drives you can simply purchase a splitter, but for additional video cards you'll do much better if the PSU has enough connectors to connect them up. You must absolutely make sure you have enough connectors for your system.
Get a computer power supply that produces quality power
Now here's an overlooked part of buying a new computer power supply. Every computer power supply has rails. Think of these as 'mini' power supplies within the unit. So for example, a one rail computer power supply is just that, one PSU, while a 4 rail computer power supply actually has 4 power supplies within it.
Why does this matter?
Well, with 4 rails you can have one rail for the motherboard, one for your drives, one for your video card and so on. If your computer power supply only has one rail, your entire system could become unstable if the video card starts demanding more power, or even if all your drives and fans are going when the weather is warm. This is more of a feature that gamers need.
The more rails you have the more stable the system will be which is of course more important for you gamers out there.
Is there anything else I should look for in a new computer power supply?
There are some additional features that are included in a high quality power supply
- Modular cable system: A computer power supply with this feature allows you to attach only the cables you need, thus reducing the clutter in your case. Without this feature, for example, if the PSU has cables to connect 4 hard drives but you only have one, the other 3 cables are still in the case causing useless clutter.
- Multiple fans: For you gamers, this is a must, even more important if you're using multiple video cards or overclocking your system.
- Flashy lights: Personally I don't care about this, its only for show. BUT, it is cool when the lights are on.
Here's an example of a top notch computer power supply available on Amazon.
How much does a good quality PSU cost?
Well, that's hard to say, it's really based on the above mentioned needs, not to mention if they are on sale or not. Keep in mind though that the wrong power supply can make your system unstable and prone to blue screen crashes so don't skimp on your PSU. I would suggest reading power supply reviews on such sites as ConsumerSearch or ConsumerReports. Power supply reviews on those sites are written by unbiased users just like yourself and often times they have the lowest prices listed right there in the power supply review. You will of course find many more useful links right here on this page too.