Hmm it seem like a low end PSU, at least reviews says its in the bronze efficiency usage, fairly wastefull about 90 watts more than a gold. But in your case it's probably okay but i'm not really sure how the S5 would work with over voltage. My ATX PSU's have a rock solid 12.05v~
I'm guessing as long as you don't see a lot of hardware errors you should be okay, what is the PCB version on the top right of the boards? I'm guessing a v1.91 would handle the over voltage fine but i don't know how the others will since i don't think they have oscillators.
You can compare your results (temps, speed, HWE%) with mine;
https://bitcointalk.org/index.php?topic=1151326.0Since then the HWE% on my S5 went up its more like 0,002% now at 393.75.
I'm still doing short 5 minute runs checking hash rates vs power vs temp at the moment. I think the thing said v1.3. Shit, is this thing loud though. Mother of god. That's why I want to try to see if I can bring the voltage down to something a bit more normal.... or slightly under. You'd think a PSU for something as expensive as a server would have a fine tune pot on it somewhere.
Also, would a normal ATX computer PSU be worth it in terms of keeping wasted power down, as opposed to this server unit?
Yeah i don't know, Servers PSU come by the shovel, some have a volt adjustment pot but i'm not very familiar with server PSU's. At the moment i have a box fan blowing 18C air from the side's so air go through the fin, the fan is at 35% and the temps is 51/53c which is excellent and the noise is acceptable. Under 60dB~
That PSU is 20$ on ebay so it's probably not something very fancy. It might also itself be loud. Anyways, in your case, money wise, no its not worth getting a 160$ EVGA G2 i'd say since you're not paying for electricity, personally, even though i have mega cheap electricity i still get good PSU to have stable power, long lasting hardware and no fires xD
But as we previously discussed, stock speed is loud as fuck. Personally i only find it bearable under 2800 RPM. A second fan or some after market more silent fan could work depending on the ambient temperature and the speed at which you run it.
Also the speed really seem to settle after 20-30 minutes. I did short runs at first too, 10 mins runs as you can see in the charts.
But anyways, for me efficient PSU's is important to keep them from generating Heat into the ambient temp, and optimizing how many miners i can get on a 15a120v breaker. For you, that's up to you to decide.
The other upside is an ATX PSU will generally be really quiet. I don't know about the server PSU you have but the server one i have even though they are 94% efficiency get really loud at 800w/1100w limit.