This web server uses a Tyan S2462 motherboard, and thus requires an oddball ATX GES power supply. Near as I can tell, ATX GES was some kind of stopgap standard used primarily (solely?) by older AthlonMP motherboards.
Today I installed a new Seasonic M12. The new powersupply conforms to the EPS12V spec, but this is easily converted to ATX GES by way of a $20 adapter. The Seasonic bears an 80 plus sticker, indicating that it will exhibit 80% or greater efficiency. I’m hoping this will lower my electric bill.

Did it work? I have Tyan Thunder K7 2462 board and I’m dying to change out the noisy power supply. Seasonics are known for being very quiet. How did the adapter work? No problems?
James,
It worked flawlessly. No problems at all. Indeed, the Seasonic is dead quiet.
I’m not sure if I realized any reduction in power consumption, because there’s a lot of “noise” in my power bill. I guess I should have purchased a Kill A Watt first :)
–Mark
Thanks Mark. Your feedback is going to help me big time. I just ordered a pair. I would have made a switch a few years back but I was discouraged after I found out it was a unique design.
I guess I’ll be able to push out more life from my aging 3DBOXX workstation I bought for $$$$. It’s still a strong system the fact that it has lasted this long and has been better performing on most applications than some other single cpu PCs in the house. But it’s a windtunnel when I turn it on and I want to dampen the noise down to match noise level of other PCs in the house which are virtually near silent.
Just out of curiosity, what is your web server housed in? I’m trying to isolate where most of the loud noise is coming from and it sounds like the special NMB 460W power supply. The case fans make a slight hum, I’ll probably also replace those with something more quiet as well. I’ve already taken care of the CPU coolers which I replaced with Thermaltake copper heatsink fans branded to be more quiet. It’s helped a little bit.
I’ve just got a typical Antec tower case, nothing special. I too replaced my 60mm cpu fans which helped a lot. For what it’s worth, I used these.