What is currently the quietest PSU

falcon26 · Post by **falcon26** » Wed Oct 08, 2008 11:14 am

What psu is currently the quietest psu in the 600-800 range...

bozar · Post by **bozar** » Wed Oct 08, 2008 12:17 pm

Enermax Pro82/Modu82. For more juice check out Zalmans HP-psus.
Anandtech also rates some silverstone psus very quiet but i don't really trust their judgement.

jhhoffma · Post by **jhhoffma** » Wed Oct 08, 2008 4:23 pm

If you're planning on replacing the PSU in your sig, you don't need 600w.

Any high quality 400+ watt PSU on the SPCR recommended list will do.

lodestar · Post by **lodestar** » Wed Oct 08, 2008 5:30 pm

Various web reviews report the system power consumption under load for the 4870 1GB as in the range of 325 - 345 watts. In my opinion putting that sort of load on a PSU of less than 600 watts capacity is not going to lead to either silence or efficiency.

So looking at the SPCR recommended list, something like the Enermax Modu82+ 625W looks suitable, but there are reports of 4870 1GB systems not booting with this PSU. So you are looking in practice for a PSU at least in the 650 watts + bracket that is quiet at at 300+ watts load.

From the SPCR recommended list this would only leave the Corsair TX650W, see the manufacturers' data on this at

http://www.corsairmemory.com/products/tx.aspx

That page also covers the Corsair TX750W. My local hardware supplier here in the UK lists the TX650 for Â£65, or the TX750 for Â£87. Both are cheaper than the price the same dealer quotes for the Enermax Modu82+ 625W.

The SPCR review for the Corsair TX650W notes that it is quiet up to about a 300 watts load, and as already noted 4870 1GB systems will exceed that. Based on Corsair's data, the TX750 looks the best option to me. There is a price premium involved, but it is not excessive in my view.

jaganath · Post by **jaganath** » Wed Oct 08, 2008 11:37 pm

Various web reviews report the system power consumption under load for the 4870 1GB as in the range of 325 - 345 watts.

they must be using the most power-sucking Phenom to get those numbers, as a non-OCed 4870 only takes 130w max:

http://archive.atomicmpc.com.au/forums. ... t=9354&p=0

sad to see that even SPCR is not immune to over-estimation of power needs so common elsewhere.

nutball · Post by **nutball** » Thu Oct 09, 2008 12:26 am

I ran a 4870 1GB + X2 5600+ under load from a Seasonic 300W PSU. I measured it pulling ~230-240W from the wall. Something squealed quite a lot, not sure yet whether it was the board or the PSU, I suspect the latter. But it seemed happy enough.

Not sure I'd run this as a long-term build, especially given the squealing... this was just a test rig, but it goes to show what you can power with what.

jhhoffma · Post by **jhhoffma** » Thu Oct 09, 2008 7:02 am

These threads go round and round, and it's hard to deal with because much of the really important information can be hard to find because the little nuggets of info are usually buried 5 pages deep in 12 page threads.

Obviously, quality matters more than quantity. Also, where the power is distributed matters quite a bit. You need enough current to power the equipment you have. You need to know how many amps your system will draw from each of it's rails: 12v, 5v, and 3.3V. Modern systems pull most of their power from the 12v lines. Many PSUs will separate their power lines into separate "rails", i.e. 12v1 and 12v2, but in actuality, these are the same rail and draw from the same source.

But to answer the question simply, and restating what jaganath and nutball have said, if you want an SPCR-approved answer, don't go by other websites power consumptions figures. SPCR reviewed the 4850 in July and unless the 4870 draws twice as much power as the 4850 (it doesn't) you will still have plenty of room with any of the lower wattage PSUs.

lodestar · Post by **lodestar** » Thu Oct 09, 2008 1:51 pm

jaganath wrote:
Various web reviews report the system power consumption under load for the 4870 1GB as in the range of 325 - 345 watts.
they must be using the most power-sucking Phenom to get those numbers, as a non-OCed 4870 only takes 130w max:

http://archive.atomicmpc.com.au/forums. ... t=9354&p=0

sad to see that even SPCR is not immune to over-estimation of power needs so common elsewhere.

The problem is that the same page that quotes 130w max for the 4870 also has a second link to a graph which gives peak 3d consumption, and this states a much higher figure of 255w, see
Charts sorted by peak 3D - http://mark. ... by3d.png

Bearing in mind that this is the calculated power draw of the card alone, and is not related to the effect on system load, then rather than over-estimation the web reviews (which generally quote system draw as measured 'at the wall') are in fact accurately reporting the power consumption of a system running this card.

SebRad · Post by **SebRad** » Thu Oct 09, 2008 3:22 pm

Hi, the chart you linked to has the figure of 255w for 2x HD4870s in CrossFire. Quite believeable as single HD4870 512/1GB versions listed as 130/131w, much the same as other figures in this thread.
I know loading my X1950pro ups the AC power by ~50w so DC power by ~40w, which is in line with their figures of 24/66w
Seb

jaganath · Post by **jaganath** » Thu Oct 09, 2008 11:59 pm

yeah, the 255w is for 2x HD4870, so 130w is the correct figure.

FartingBob · Post by **FartingBob** » Fri Oct 10, 2008 6:13 am

unless you have high end SLI/xFire and a dozen drives i cant see any need to use a 600w+ PSU. But that doesnt stop people buying those rediculous 1KW models, never reaching more than about 40% capacity...