Old PSU?

J. Sparrow · Post by **J. Sparrow** » Tue Jul 14, 2009 7:01 am

I'm re-building a machine on the cheap, and have an old 235W PSU lying around from the pre-ATX12V era; the 12V rail rating is 8.0A, or 96W. The machine would run an undervolted Winchester A64 and one 3.5" HDD, used to pull about 40-45W during normal operation.

I'm mostly concerned with peak absorption, and I could really use some advice as everything I have found on the 'net is using inflated figures like TDPs and other silly stuff.

Do you think this PSU is enough for the job?

jhhoffma · Post by **jhhoffma** » Tue Jul 14, 2009 1:05 pm

Shouldn't be a problem. Does the mobo need a 4-pin 12v P4 connector?

DanceMan · Post by **DanceMan** » Tue Jul 14, 2009 3:03 pm

Likely no issue with the 12V power. Some of the old psu's you salvage out of old pc's are generic junk, but you'll find a few made by FSP and CWT under other names. The quality of the power is probably better from those. PowerMan psu's are often among those.

J. Sparrow · Post by **J. Sparrow** » Tue Jul 14, 2009 3:16 pm

Yes, when I said it's pre-ATX12V I meant exactly it lacks the 4 pin power connector for the CPU. The board won't power up unless I get an adaptor.

The PSU is an older ATX unit, pre 1.x specification, so the 5V line is stronger and the 12V weaker than current units.

TBH I'm concerned about frying up the board?

edit: @DanceMan the unit is CWT branded.

DanceMan · Post by **DanceMan** » Tue Jul 14, 2009 3:30 pm

Ohm's law tells me that 50 watts at 12v is just over 4A. I don't think you need worry. That CWT should actually deliver its rated power and ripple should be reasonable.