New PSU for friend's PC

[scottmso]

I have a friend with a system (old Asus nForce mobo, Athlon XP 2000+, 512MB RAM, 2 7200RPM HDs, 2 optical drives, Radeon 9800 Pro) that had a crappy Allied PSU (that I told him to replace a while back) that recently blew out and possibly took out some things.

Obviously he needs a new PSU. I'm trying to help him decide. He seems to want to buy something online for less than $40-50, however he's not too eager to spend a lot on a PSU. I'm sure that a FSP 300W would work great, however he is planning on upgrading to an Athlon 64 and maybe 1GB of RAM soon. And the prices on the FSP PSUs have gone up anyway.

He asked me if these two are good:

http://www.newegg.com/Product/Product.asp?Item=N82E16817171003 - Cooler Master 430W $34 shipped - this one sorta scares me because it has the "generic" look and I've never really heard much about Cooler Master's PSUs.

http://www.newegg.com/Product/Product.asp?Item=N82E16817153006 - Thermaltake 420W $38 shipped - I've heard good things about Thermaltake's PSUs (made by Sirtec?) but I've heard bad things about the low-end ones in particular.

I'm not sure which of these two have SATA connectors (he may or may not want them in the near future.)

However, I recommended that he get a Sparkle from Newegg, or on second thought, ZipZoomFly (since they are often cheaper on PSUs.) I was thinking about one of the 350W units, or maybe even a 400W I see on ZZF for $56 shipped. What do you think?

 

[jonnyGURU]

My only reservation about getting one of those Coolermaster's or anything with either a high 12V or dual 12V rails is that your friend's PC regulates CPU power off of the 5V rail. The end result is a power supply that runs over spec on the 12V (potentially damaging components that use the 12V rail) and an under spec 5V (limiting CPU performance and overclockability.)

The Thermaltake would be a better choice for him, although when he switches to an A64 system, he should sell the PSU as part of a bundle with the old mobo and CPU because it will be about as useful as the Deer he has now in that new system. ;-)

Perhaps he should just wait altogether?

 

[Culvin]

The end result is a power supply that runs over spec on the 12V (potentially damaging components that use the 12V rail)...

Are you saying that using a psu with a strong 12v-rail on a system with an older 5v-rail cpu is potentially damaging? I've read in various forums that too much power should never be a problem.

 

[jonnyGURU]

I think you're confusing "too much wattage" with "too high of voltage."

A PC only uses as much "wattage" as it needs. So you can slap a 600W power supply in a Pentium III 600. No harm, no foul.

The prolonged over-voltage however, can cause excess heat. With his motherboard, I'm sure the only ill effect would be a hard drive failure or possibly an AGP card failure. On the flip side, too low of a voltage can cause instability, lack of ability to overclock, etc.

Either way, he's within spec. So you have to assume that everything is peachy. But how long can a component tolerate being run 5% over volt? I don't know. There may be a good answer out there, but then again... MTBF ratings are calculated from averages and not actual failures, so.....

 

[KoolDrew]

Don;t even consider a Thermaltake. They droop their rails under load. Definitely not recommended.