your power draw @ the wall with 4x?

[staraptor]

Could you guys with 4 cards in one sys post your power draw at the wall along with what cards you have

[jme621]

Could you guys with 4 cards in one sys post your power draw at the wall along with what cards you have

which cards?

[faille]

4 x 6950 on an i5 2500k = 820 from the wall

[trentzb]

4 x 5850 on Sempron = 620W at wall / 1400 Mh/s

[sethmo]

4 x 5850 on Sempron = 620W at wall / 1400 Mh/s

Cool, I will have two setups of 4 5830s on Corsair 750psu, was worried that I would be getting close to the limit of my psu.  Should be good

[trentzb]

Careful, those numbers are not stock. Highly tweaked. Same rig not tuned running ~350 Mh/s pulls  closer to ~800W at wall. 5830s usually pull a bit more than 5850s.

[faille]

don't forget to factor in your PSU efficiency, and try to leave a little headroom on top if you can.

[newunit16]

i run a 4x 5830 rig, sempron 1ram module, hdd.
2x power supplies feeding it all. 620w and a 530w. both 80%+ certified
740 max watts from the wall.

[Fletch]

4 x 5850 on Sempron = 620W at wall / 1400 Mh/s

Seems about right. I'm running 3 x 5850 on Sempron and I measure about 480-490 W. I have a 600W 80+ Gold PSU (effeciency 540W) so there's a bit of headroom, but not a lot.

[newunit16]

I have a 600W 80+ Gold PSU (effeciency 540W) so there's a bit of headroom, but not a lot.

people seem to read efficiency wrong. if you have a 1000w power supply rated at 80% efficient, it doesn't allow 800w. it allows 1000w, but it will draw 1250w from the wall. 1250w at 80% is 1000w. you get the power advertised, but the power supply will use X% more, where X is 100-efficiency rating.

another note, peak efficiency is usually around 20-75% load on the power supply.

[blackgold]

Unit is correct. When reading a power supplies rated efficiency such as 80, 85.. whatever is not shown i.e 100-80=20% is what is lost in the conversion from wall power to make the power... So if your power supply can deliver 1000w @ 80%, then the power from the wall must be 20% greater to make up for loss.

[johnyj]

I don't really understand

Is this mean, if I measured 500W at the wall, the PSU only output 400W to supply the whole machine?

[macharborguy]

I have a 600W 80+ Gold PSU (effeciency 540W) so there's a bit of headroom, but not a lot.

people seem to read efficiency wrong. if you have a 1000w power supply rated at 80% efficient, it doesn't allow 800w. it allows 1000w, but it will draw 1250w from the wall. 1250w at 80% is 1000w. you get the power advertised, but the power supply will use X% more, where X is 100-efficiency rating.

another note, peak efficiency is usually around 20-75% load on the power supply.

good to know, but also reading it wrong is beneficial in a way, since they aren't pushing the PSU as hard as they could be.

[vapourminer]

I don't really understand

Is this mean, if I measured 500W at the wall, the PSU only output 400W to supply the whole machine?

at 80% efficiency, yes.

power supplies have "sweet spots" on their efficiency curve, the manufacturer should have a chart. one may peak at 50-80 % load, another at 75-85% load. they vary. but 80+ certified means it will never be below 80% no matter what the load.

[haploid23]

my highest outputting rigs has 3x 5850 and 1x 5870, all overclocked, draws about 750w from the wall using a 850w gold efficiency PSU

[Morebitcoinsplease]

I haven't got the readings but I pull straight from the wall several rigs with UPS battery backup

One setup I have is

(1) Wall Jack handles 7 GPU Cores
1200w PSU with 1x5850 3x5970's

The other is

(1) Wall Jack handles 4 GPU Cores
1200w PSU with 4x5850's

So you should be good pulling from the wall I know I can put 8 GPU Cores on one wall socket on a 1200w PSU

But keeping in mind those rigs are the only items on that entire circuit, I don't plug anything else in them.

[teukon]

Unit is correct. When reading a power supplies rated efficiency such as 80, 85.. whatever is not shown i.e 100-80=20% is what is lost in the conversion from wall power to make the power... So if your power supply can deliver 1000w @ 80%, then the power from the wall must be 20% greater to make up for loss.

Wouldn't the draw at the wall be 25% greater?  If a PSU draws 1250W from the wall and is 80% efficient then it is supplying 1250W * 80% = 1000W to the miner.

Honestly I don't know what the efficiency rating on the PSU means but if by 80% they mean that only 80% of the power it receives is passed on then the draw at wall would have to be 1250W.

[trentzb]

Honestly I don't know what the efficiency rating on the PSU means but if by 80% they mean that only 80% of the power it receives is passed on then the draw at wall would have to be 1250W.

Yep, this is what is means.

[malavita]

Does anybody know total power consumption for 5 X 6970 - just cards, not PC obviously.

Thx!!!

[cicada]

Does anybody know total power consumption for 5 X 6970 - just cards, not PC obviously.

Thx!!!

I can estimate it for you - 6970's pull ~160-200W, so 5x would be somewhere between 800 - 1000W

Google + simple math = your friend.

[edit][disclaimer] I don't own these cards (I do own 6950s with similar draw), and this is not taking OC into consideration.