Which PSU for Dual 8800 GTX's?

CoronasRGood · Post by **CoronasRGood** » Sun Jan 21, 2007 4:11 pm

Hello all,

I am currently in the process of building the following:

P180
Asus Striker Exreme 680i
Intel Core 2 Extreme Quad-core QX6700
3 WD 150GB Raptors
2 XFX 8800GTX XXX edition
Corsair Dominator 2GB memory
Plextor 755SA Burners

Now the question. I have been checking around and i see that on the SLI Zone website they recommend at least a 750W PSU. I was considering buying the Corsair HX620 but now after reading this I am concerned. I would like a quiet PSU but i am unsure how quiet these things are at 750W+. Any recommendations would be appreciated.

burebista · Post by **burebista** » Sun Jan 21, 2007 9:18 pm

IMO CorsairHX 620 should do the trick, but if you have in mind to heavily OC your rig maybe you should consider an Seasonic M-12 700.

SnooP · Post by **SnooP** » Sun Jan 21, 2007 9:20 pm

No psu will be quiet at even 500w, though corsair will be better than most. Corsair hx620w should be fine, especially if your running at stock. Though keep in mind its only got 2 pcie connectors, so you'll have to waste quite a lot of molex's on the 8800gtx. Perhaps consider an 8800gts instead (only needs 1 per card)? As suggested if your set on 8800gtx then the m12 700w is a better choice since its got 4 pcie connectors

EsaT · Post by **EsaT** » Sun Jan 21, 2007 11:59 pm

Anandtech got ~520W peak wall consumption for 8800GTX SLI PC. That translates to ~440W load at most after losses in PSU. They used X6800 and had fewer HDs but about 500W should be still enough.
(using TDP values for CPU and GPU would give about 500W for them)

student · Post by **student** » Mon Jan 22, 2007 7:23 am

I hope your monitor is a 30inch 2560x1600 monstrocity or you spend all your time on a 1600 x 1200 + monitor outdoors in Oblivion, otherwise 2 x 8800GTX in Sli is a waste of money. You will get playable FPS with one 8800GTX.

I bet Anandtech's figures didn't stress the system with DX10 benchmarks / games? A demanding DX10 game will probably see the 8800GTX consuming a lot more power.

The Corsair 620HX will provide plenty of juice for 2 x 8800GTX in sli.

Power Consumption:
2 x 8800 GTX in Sli = 370W
Overclocked Top Spec system = 200W

Power consumption = 570W mostly on the +12V rail

Corsair 620HX will provide 600W on the +12V rail.

If you are going to add 3 more Raptors and overclock the bejesus out of everything using liquid cooling then you might consider a Seasonic M12-700 which will give you a nice 672W on the 12V rail.

EsaT · Post by **EsaT** » Mon Jan 22, 2007 7:41 am

student wrote:I hope your monitor is a 30inch 2560x1600 monstrocity or you spend all your time on a 1600 x 1200 + monitor outdoors in Oblivion, otherwise 2 x 8800GTX in Sli is a waste of money.

I would be more worried about that god damn awful idle power consumption of 8800GTX which is something above 50W per card!