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Topic: Will my 850W PSU power 5970 + 5870 + 5870? (Read 1479 times)

full member
Activity: 164
Merit: 100
September 15, 2011, 12:57:57 AM
#11
Apologies for bumping an old thread (well, sorta old anyway) but I've been running my two 5870s + single 5970 for a couple weeks now without any problem.  Power at the wall reads right at 850W +/- a few Watts but I have that issue where my CPU is pegged at 100% usage when I'm mining, so I'm guessing that's drawing a few watts.

So anyway at lunch today I went and bought a new Corsair AX1200.  It's so square and round and fuzzy and I can pets him Smiley  I'm probably going to return the AX850 and run my rig on the 1200 instead.   So now my question is:  Can I run my two 5870s + 5970 + a 6990 off one AX1200?  I can't seem to find a buyer for my 6990 (https://bitcointalksearch.org/topic/sold-msi-radeon-hd-6990-brand-new-in-box-43682) so I'm leaning toward just ripping it open and installing it into my system.

I think you can. I am running 3 5970 on my msi 890fxa

thats 6 GPU. I have them OC to 1075v and 825. Anything more is not stable.
My power draw is 1000-1030watts.

I am using cool master silent pro 1200W

hero member
Activity: 896
Merit: 1000
Seal Cub Clubbing Club
September 14, 2011, 07:13:15 PM
#10
Apologies for bumping an old thread (well, sorta old anyway) but I've been running my two 5870s + single 5970 for a couple weeks now without any problem.  Power at the wall reads right at 850W +/- a few Watts but I have that issue where my CPU is pegged at 100% usage when I'm mining, so I'm guessing that's drawing a few watts.

So anyway at lunch today I went and bought a new Corsair AX1200.  It's so square and round and fuzzy and I can pets him Smiley  I'm probably going to return the AX850 and run my rig on the 1200 instead.   So now my question is:  Can I run my two 5870s + 5970 + a 6990 off one AX1200?  I can't seem to find a buyer for my 6990 (https://bitcointalksearch.org/topic/sold-msi-radeon-hd-6990-brand-new-in-box-43682) so I'm leaning toward just ripping it open and installing it into my system.
legendary
Activity: 1988
Merit: 1012
Beyond Imagination
August 25, 2011, 09:23:58 PM
#9
I have such a setup, about 620 W total measured from wall, no voltage overclocking, 5870 running at 900 Mhz, 5970 running at 750/730Mhz, mem all 300Mhz
sr. member
Activity: 406
Merit: 257
August 25, 2011, 07:57:12 PM
#8
If they aren't overvolted... I'd say "yes, but".
The AX850 is a pretty good PSU, just look at JGs review Wink
OCed 5870 at stock V is 200-220W, like 180 with mem @ 300
OCed 5970 at stock V is ~300W, about 270 with mem @ 300
Stock wattage is ~ the same as OCed with underclocked mem.
So that's < 700W load on a PSU rated for 840W continous on 12V.
now, theres the "but" part... simple, I wouldn't want to run a PSU at > 80% rated 24/7 for months.
hero member
Activity: 784
Merit: 1009
firstbits:1MinerQ
August 25, 2011, 07:46:30 PM
#7
For a low power supplemental PSU I'd go with the low-cost Corsair CX500 or CX600. They're pretty cheap (especially if on promo) but not dirt cheap like some junk supplies. The thing is you know it's going to work well and it's great for starting a new system that you haven't got all the cards for yet.

If you do be sure to get the V2 version as it's a better rated newer design. Right now the CX500 is $35 with 10% coupon code and with rebate at newegg but I recall somewhere it being said they've gone as low as $15 at one time.
full member
Activity: 196
Merit: 100
August 25, 2011, 05:34:30 PM
#6
Maybe I can just buy a cheapo 300-400W PSU to supplement my main one in the mean time.

That's a wise idea regardless of your situation.  I'm going to pick up a spare just for that inevitable 'the PSU is down' moment.
hero member
Activity: 896
Merit: 1000
Seal Cub Clubbing Club
August 25, 2011, 03:39:58 PM
#5
theres only one way to find out but most likely youll need to use your old psu too. there are youtube vids how to wire 2 psu's together its pretty simple

Damn, I haven't even sent my old PSU back to Thermaltake yet.  Oh well, I still have a few days before the 5970 gets here.  Maybe I can just buy a cheapo 300-400W PSU to supplement my main one in the mean time.
full member
Activity: 182
Merit: 100
August 25, 2011, 03:12:43 PM
#4
If it wasn't a corsair I'd say no. Since it is maybe. I'm pretty sure the graphics cards alone will take up about 700 watts maybe more.
full member
Activity: 182
Merit: 100
August 25, 2011, 03:11:47 PM
#3
theres only one way to find out but most likely youll need to use your old psu too. there are youtube vids how to wire 2 psu's together its pretty simple
legendary
Activity: 812
Merit: 1002
August 25, 2011, 03:03:50 PM
#2
it should, but it'll be very close
hero member
Activity: 896
Merit: 1000
Seal Cub Clubbing Club
August 25, 2011, 01:11:15 PM
#1
I just bought a Corsair AX850 last weekend and I just ordered a new 5970.  My question is, will my PSU be able to handle my 5970 plus two 5870s?
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