My power supply broke down.
Please help me choose a power supply that's right for my computer. What specifications should I look for while shopping (there are so many variations).
Thanks in advance and have a nice day.

Would help if we knew what type of computer it is, motherboard, video card(s), how many peripherals are you running (total), what kind of hard drives are you running and how much upgrading do you want the supply to support.

This would tell us what kind of connectors you need and how large of a power supply would be best in the long run.

Here's a link to a PSU requirement calculator. Enter your hardware specs to get a general idea of what size PSU you would need.

Bear in mind there are other considerations beside raw wattage ie quality, stability, cooling etc

Haven't seen that before. Using a 600 watt power supply to give a little more play room but it was close .

mdg, that Flash based calculator seems to be lacking any recent power-hungry GPUs.

EIGHT, today's PSUs should be 80PLUS, a standard to show they are always 80+% efficient. Equally important to note is that they all perform best between 50-75% load, that is a stupidly high 800W PSU won't be doing very well with a regular desktop only asking 200W of it.

Usually your graphics card and motherboard will dictate your needs for the 12V rail's Amp rating and the connection required to the board, and your other internal drives and devices may require old or very recent power connectors.

Personally I've had a couple of Antec PSUs, and one with a 120mm fan was basically silent. I don't suggest fanless or cheap brand but high W rating units.

Yes, also lacking the Core2 Duo's and AMD X2's. The site says the calculator is being "recreated", maybe they'll add in the newer CPU's and GPU's.

A power supply calculator is useless because they are never accurate. An 80Plus feature of a power supply does not show much. I recommend power supplies with active power factor controlled and universal voltage (no 120/240 switch). I suggest 300 watts for the economy setups. For setups with a few hard drives and a dedicated video card, 400 watts or more. SLI will need about 500 watts or more. I suggest power supply brands such as Eneramax or Seasonic. Antec power supplies are poor.

A Kill-a-watt meter will help figure out how much the computer is consuming, but watch what setting you are reading from.

I wouldn't say they're useless. Sure, they are not accurate, but they will give you a general range (eg 400W), to which you can apply other criteria and whittle down your choices.

The only really accurate method I know of would be to physically measure the power requirements of all your specific hardware and base a choice on that.

I usually base my choices on manufacturer and quality and less on the actual power.