Old PSU, confused about the wattage...

icalebkim

Honorable
Oct 6, 2012
8
0
10,510
So I'm starting my budget desktop build. After hunting around in the garage for spare computer parts, I came across an old PSU that I could use for my build.

I checked the input (100-240V, 47-66 Hz) and the mains power supply is in that range (240V, 50Hz)

Output confuses me. I get a lot of different values (ie +5V.../21A, +3,3V...15A). On the bottom it has the following:
Max combined power on: 3,3V and +5V: 110W
Max continuous output power: 460W

So from the following information, does that mean that my PSU is capable of delivering 460W?
(Yes, I know, 460W on paper doesn't mean to have a build that requires 460W. I plan to have my build to have a far lower power requirement.)
 
Solution
Thats not too old of a unit, it at least has active PFC on it.

That means it is rated for 460W of continuous power at some temperature. If it doesn't really have a brand name on it assume it is rated at 20C and derate it by 5W/C of ambient temperature above that to be safe. Low power PSUs really aren't expensive so if it seems a bit sketch and you are putting good parts in the system i'd just drop the $25 and pick up a newer unit.
Thats not too old of a unit, it at least has active PFC on it.

That means it is rated for 460W of continuous power at some temperature. If it doesn't really have a brand name on it assume it is rated at 20C and derate it by 5W/C of ambient temperature above that to be safe. Low power PSUs really aren't expensive so if it seems a bit sketch and you are putting good parts in the system i'd just drop the $25 and pick up a newer unit.
 
Solution