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Topic: your power draw @ the wall with 4x? (Read 3072 times)

hero member
Activity: 812
Merit: 502
July 21, 2011, 06:04:23 PM
#22
800W for what is in the signature
member
Activity: 90
Merit: 10
July 20, 2011, 01:58:55 PM
#21
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.


Great - thanks!!!
full member
Activity: 196
Merit: 100
July 20, 2011, 01:52:01 PM
#20
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.
member
Activity: 90
Merit: 10
July 20, 2011, 01:42:49 PM
#19
Does anybody know total power consumption for 5 X 6970 - just cards, not PC obviously.

Thx!!!
sr. member
Activity: 406
Merit: 251
July 19, 2011, 06:07:51 PM
#18

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.
legendary
Activity: 1246
Merit: 1011
July 19, 2011, 05:20:23 PM
#17
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.
member
Activity: 84
Merit: 10
July 19, 2011, 01:00:55 PM
#16
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.
legendary
Activity: 812
Merit: 1002
July 18, 2011, 01:25:24 PM
#15
my highest outputting rigs has 3x 5850 and 1x 5870, all overclocked, draws about 750w from the wall using a 850w gold efficiency PSU
legendary
Activity: 4354
Merit: 3614
what is this "brake pedal" you speak of?
July 18, 2011, 05:46:16 AM
#14
I don't really understand Huh

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.



newbie
Activity: 42
Merit: 0
July 17, 2011, 10:22:29 PM
#13
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.
legendary
Activity: 1988
Merit: 1012
Beyond Imagination
July 17, 2011, 10:14:55 PM
#12
I don't really understand Huh

Is this mean, if I measured 500W at the wall, the PSU only output 400W to supply the whole machine?
newbie
Activity: 21
Merit: 0
July 09, 2011, 05:42:31 PM
#11
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.
member
Activity: 133
Merit: 10
July 07, 2011, 07:02:44 PM
#10
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.
full member
Activity: 168
Merit: 100
I'll have a steak sandwich and a... steak sandwich
July 07, 2011, 03:43:09 PM
#9
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.
member
Activity: 133
Merit: 10
July 07, 2011, 07:32:21 AM
#8
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.
newbie
Activity: 38
Merit: 0
July 07, 2011, 12:58:36 AM
#7
don't forget to factor in your PSU efficiency, and try to leave a little headroom on top if you can.

sr. member
Activity: 406
Merit: 251
July 07, 2011, 12:22:08 AM
#6
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.
newbie
Activity: 24
Merit: 0
July 06, 2011, 10:36:16 PM
#5
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 Smiley
sr. member
Activity: 406
Merit: 251
July 06, 2011, 09:56:58 PM
#4
4 x 5850 on Sempron = 620W at wall / 1400 Mh/s
newbie
Activity: 38
Merit: 0
July 06, 2011, 09:44:52 PM
#3
4 x 6950 on an i5 2500k = 820 from the wall
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