Hardware: DIY Power – How much?

In building my new computer I needed to verify my calculation of the amount of power required. What size power supply do I need?

By my, mostly in my head, calculation as I selected parts I need 500-550 watts at peak demand. I select a continuous supply rating based on my anticipated peak demand. While power supplies have built in the ability to handle peak loads that exceed their continuous rating and that often gets advertised, that ability usually comes from considering what all the parts can stand when pushed to >100% of their design spec.

Computer Power Supply

Computer Power Supply

Humans can walk all day at 5 mph. But, we can only run at 20 mph for a few minutes. Sort of the same thing with computer power supplies. At some point in time they overheat or an individual component overheats by too much and the unit fails. Some units have anti-self-destruct protection, which reduces the power supplied to save itself. And what does that do to the rest of the computer? Nothing good.  Continue reading