SPCR

I'm moving from an old noisy and power hungry setup to a newer one, faster and more efficient, but I'm considering if is really a good idea to swap the PSU too, a FSP Group Aurum AU-600 (gold rated, 80+) mainly for two reason: 1) it's a bit loud, and 2) may be overpowered.

1) noise: swapping fan?

I did this trick ages a couple of time to fix bad fans or simply noisy PSUs, but I'm concerned is the right thing to do with this one. I have no idea if the actual fan is thermally controlled in the outside or by the fan itself, and if changing the fan with one that has a fixed low RPM would be a good idea.
Apart from voiding the warranty, what's the general opinion here on SPCR about swapping the fan on PSU with quieter models?

Update: there's a Protechnic 2400rpm fan inside, the spec say is PWM (regulated with a bad linear system by the PSU).
I'm considering buying a 1200-1300 max PWM fan. Do you think is a good idea?

2) overpowered but efficient?

I'm planning to build a 65W Haswell with a mid-sized GPU, 1HD, 1SSD, PCI-X audio and not much more. 600W seems a lot for what I'm planning to do (Tt calculator say that I need less than 400W), but if efficency at low wattage is ok with this AU-600 maybe it's ok to keep using it, am i right? Problem is I don't know how good this PSU is with small loads. Any idea where to verify this?
Do I really need to switch to 460-500W to save in efficiency?

http://www.xbitlabs.com/articles/cases/ ... m-psu.html
Review for the FSP Aurum AU-700, Aurum CM AU-650M and AU-750M. On pages 2 and 4 there are performance graphs including crossload voltage regulation, ripple and noise and efficiency and power factor. So you can look at the efficiency and power factor graph for those units and possibly get a rough idea what the efficiency curve of the AU-600 is as well.
I don't know of any other useful reviews for the FSP Aurum series, at least not in English or that provide detailed results or graphs.

As you know the AU-600 uses a Protechnic Electric MGA12025HF-A25. The first A in MGA12025HF-A25 denotes that the fan uses a 2-pin connector, according to the 'remarks' on the Protechnic website last time I checked.

Personally I think that if you don't need the unit to deliver it's full rated output (ie 600W), indeed much less than this, then there shouldn't be any harm in using a slower fan - as long as you know what you're doing.

If it is a Gold 80+, the amount of heat the PSU generates internally is puny. So I would have no hesitation whatsoever make the fan swap you're considering. A 1200rpm PWM would probably be perfectly fine. Just check the original fan and see if it really is a 4-line fan, because the photo from the xbit labs shows a 2-lead fan, which can only be a pure DC voltage fan.

MikeC wrote:If it is a Gold 80+, the amount of heat the PSU generates internally is puny. So I would have no hesitation whatsoever make the fan swap you're considering. A 1200rpm PWM would probably be perfectly fine. Just check the original fan and see if it really is a 4-line fan, because the photo from the xbit labs shows a 2-lead fan, which can only be a pure DC voltage fan.

Seems FSP went wrong describing the fan as PWM. The Protechnic included is a 2-wire fan controlled by the archaic linear voltage which is the cause of the terrible fan regulation.
I found an old thread of a user that swapped the fan with the Enermax Magma, which is known to have a low starting voltage. It's a 1500 RPM, but considering that even 2000 was a little too much (tried before), I'm thinking maybe to go even lower to a 1350 RPM fan.
I just need to find a good one with low starting voltage... any ideas where to look for a table or something?

Or you could get any fan you want and plug it in your MB, or your PSU Molex connector
Like MikeC said, a gold PSU will not spit out a lot of heat... I replaced a bad Enermax fan with a Noctua fan, plugged it in a molex connector with the LNA adaptor, and I couldn't be happier. The air that comes out of the back of the PSU is barely warm and I didn't have to worry about adapting the fan. And it's quiet.