5x280x Rig | 1750w will cut it?

[gilad215]

hello guys.

planning on buying 5x gigabyte 280x's and getting them together with Asrock h81 PRO BTC.
along with them:

1xCoolermaster V1000 1000W - MB+CPU+3x280x
1xCorsair CX750 750W - 2x280x

do you think its enough? the thing is is heard that no matters who powers the gpu the gpu will take about 50w from the PSU connected to the board. is this a problem?

thank you

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[bjalbert]

Yes if you undervolted to at least 1.15v and don't OC your cpu. I have a rig with 1760W platinum PSUs and at the wall 3x 280 cards and mobo(OC) use like 970w and the 760w PSU running 3 cards and the powered risers is around 720 watts.

It is close. Get a 1000w and an 850w PSU to be safe and at least have some headroom. Each 280x card uses around 250w when mining

[crazyates]

All of our 5x Gigabyte 280x rigs are now on 220v, so I can't test them, but I do have some numbers from back when they were running on 110v, and I was using my killawatt.

At 1.01v, the whole rig used 1250W
At 1.05v, the whole rig used 1300W
at 1.13v, the whole rig used 1450W
at 1.20v, I don't have any numbers, but I believe I had estimated somewhere around a 1550W power draw.

All numbers are at the wall.

Some cards came with a stock 1.13v, and others came with a stock 1.20v. The 1.13v could be undervolted to 1.01-1.05v, and the 1.20v could be undervolted to 1.07-1.1v.

I would say at the very least, you could undervolt to 1.1v, and get around a 1400W power draw. We're running almost 30 of those Gigabyte 280x, and I've never had one not work at 1.1v.

So the end result is a 1400W power draw, and yes, 1750W of PSUs would be more than enough. We used two 750W Rosewill, and worked great.

[Prelude]

1750w is way overkill. I run 5x undervolted Sapphire Dual-X 280x on a single Seasonic 1250w.

[skleven]

1750w is way overkill. I run 5x undervolted Sapphire Dual-X 280x on a single Seasonic 1250w.

I run 2x Dual-X and 1xToxic on a Corsair 850w. At stock voltage. So i also belive 1750w is overkill. But if that`s the two PSU`s he got, he will do fine.

[gilad215]

1750w is way overkill. I run 5x undervolted Sapphire Dual-X 280x on a single Seasonic 1250w.

I run 2x Dual-X and 1xToxic on a Corsair 850w. At stock voltage. So i also belive 1750w is overkill. But if that`s the two PSU`s he got, he will do fine.

Its So Wierd that your Corsair 850w Deals with them!
i have a corsair cx750 which can't handle 2x290 even at -10 powertune. had to exchange one in 280x.

i heard that any gpu with the board ill use H81 PRO BTC consumes 50W+ from the psu that connects to the board even if another psu powers the 6+2PIN. guess ill undervolt all of them?

[bjalbert]

Sorry I was thinking you were running 6 cards. So yeah what they said killawatt is a great tool.

[skleven]

1750w is way overkill. I run 5x undervolted Sapphire Dual-X 280x on a single Seasonic 1250w.

I run 2x Dual-X and 1xToxic on a Corsair 850w. At stock voltage. So i also belive 1750w is overkill. But if that`s the two PSU`s he got, he will do fine.

Its So Wierd that your Corsair 850w Deals with them!
i have a corsair cx750 which can't handle 2x290 even at -10 powertune. had to exchange one in 280x.

i heard that any gpu with the board ill use H81 PRO BTC consumes 50W+ from the psu that connects to the board even if another psu powers the 6+2PIN. guess ill undervolt all of them?

I`ve had one of those cx750w. And it could not handle more than 2x 7950. Tried 3x7870, but no. But there is a big difference between that, and the one i got now. That`s a hx850w. Your is also bronze, and mine is gold certified. But i must say that i was suprised when it worked. And it have been working for almost 4months now.

[zvs]

hello guys.

planning on buying 5x gigabyte 280x's and getting them together with Asrock h81 PRO BTC.
along with them:

1xCoolermaster V1000 1000W - MB+CPU+3x280x
1xCorsair CX750 750W - 2x280x

do you think its enough? the thing is is heard that no matters who powers the gpu the gpu will take about 50w from the PSU connected to the board. is this a problem?

thank you

well, you dont even tell us if they're bronze/silver/gold/plat cert.  i guess i could look up the models but i'm way too lazy.

i used to run three 5970's on a 750 watt gold cert seasonic in 100oF ambient

most of the gold cert psus will be about to put out 5-15% more than the watts shown, it'd just be horribly inefficient energy wise.  most of the non-cert, 100oF and running at 75% load = dead psu

and some just use better components, eg my two 850w thermaltake toughpowers that i've had for 6 years