posted on Mar, 28 2012 @ 04:27 PM
The posters above are correct.
Your PSU can have as much wattage as you like, the PC will only draw what it needs.
When you're looking for a decent PSU, the really important stat is the number of AMPS on the +12 rail (or rails), because this lets you know exactly
how much power is being made available to your components.
What you're looking for is this.
You need enough watts to power all of the components in your system. For a PC with a quad-core processor, a couple of hard drives, DVD drive and
video card, you'll probably want at least 500 watts. In order to power those components, you'll want an absolute minimum of 40 amps on the +12v
rail (or, if the PSU has multiple +12v rails, they need to add up to at least 40 amps. 40 is okay, 50 is good, 60+ amps is GREAT). Also, try to make
sure that your PSU is efficient. Anything above 80% efficiency is good. Once you get above 80%, PSU's are certified - bronze, silver, gold ratings
for efficiency, the higher the better.
I'd be really surprised if the PSU wasn't at fault in your scenario. 250w (which will no doubt have very few amps on each rail, too) simply isn't
enough to power your components. The second possibility is overheating. Not having thermal paste on your CPU means that the heat transfer will be
poor - and the CPU will retain more heat (MUCH more heat) than it should. Once your CPU overheats, the PC will automatically shut down to protect
Hopefully that helps.
Keep posting back and let us know how you go!