PSU for 2x5870

[tvasconcelos]

Hi, just wondering if someone can help me on this. I have now a 5870, i'm pulling 450MH/s from it on BAMT with a 550w PSU. I'll maybe had another one, i'll have to upgrade the PSU. In those online calculators, i used this one http://extreme.outervision.com/PSUEngine, it says a minimum 568w and recommended 618w.

It assumes that all my components will be at 90% load. The cards are but the cpu is almost idle all the time. Can someone give me a hint on a good PSU, or what are your experience with similar setup??

I didn't want to invest a lot on hardware right now since the ASIC's are announced and the reward halving, the difficulty rising etc... but with only 450MH/s i'm struggling to have some return that i can actually be proud.   

[1715315562]

1715315562

[1715315562]

1715315562

[50BTC.com]

On factory clocks you can use your 550W PSU.

[ssateneth]

I probably really should get a per-GPU power draw.. I  did one for a 5970 and it was something like 220W full load for both GPU's compared to not being connected or powered at all, but it was also undervolted.

You should have more than enough room on your current PSU. Right now I'm powering 8 (yup, driver limit) Cypress XT (5870/5970) GPU's off of a 1000W PC Power & Cooling 1KW-SR. Somehow, overcurrent protection hasn't kicked in.. I'm drawing 1050W AC and the PSU is about 83% efficient.

[zvs]

i run two 5970's on a 750W seasonic, if it's a good 550w psu it shouldnt have any problems.

at least if you dont have a whole bunch of peripherals.  

i underclock cpu (and disabled the second core, since it was a dual core), turn off built in audio, leds, a network port, use a USB stick, etc

(ed: i'd be more worried about the amps on the 12v rail)

[tvasconcelos]

Hi, thanks for your answers.

I actually run BAMT, from a USB stick. no hdd, no cdrom, no nothing. it's headless, no keyboard, no mouse...
the cpu is a p4 3.2 prescott i think, it's sucks a bit. 2 sticks of ddr2 and nothing more unless the graphic card.

Guess i'll check what PSU it is and the true specs before switching on a second gpu.

thanks...

[Coinoisseur]

Yes, brand and 12V rail rating is important for determining how likely it is to work out well.

[AndrewBUD]

I have two 5850's overclocked on a Thermaltake TR2 600watt....


seems fine.. Getting warm but no issues