280x cards power usage?

[cisahasa]

how much power is needed to run 3pieces radeon  280x cards?
700w too small power?

[Gamer67]

700 will not be enough.

[ballot]

i will buy 2x psu for my 6x 280x
1250w for 3x 280x and motherboard hdd cpu ram etc..
1000w for 3x 280x
is it enough 

[Camilio]

wait.. you aren't going to run all gpu's with one MB and 2 psu's, arent you?

[Undefeatable]

how much power is needed to run 3pieces radeon  280x cards?
700w too small power?

Suggest to go at least 1000w. If you overclock much then a single card can draw up to 350w

[crazyates]

Our 5x 280x rig was pulling 1450W at the wall.

After we undervolted, that same rig was pulling 1250W.

Take away 100W for the system, and that's 1350W and 1150W for the GPUs.

That's 270W and 230W for each GPUs.

Those numbers were at the wall. These were on 80Plus Gold PSUs, on 110V, somewhere around 80-90% load, so the PSUs were ~88-89% efficient.

This means that the GPUs were pulling 240W (stock volts) and 205W (undervolted) from the PSU.

For 3 GPUs, you would need a 850W PSU (240x3=720+100=820). If you're undervolting, you would need a 750W (205x3=615+100=715).

If you're running high volts or massive OCing, then you can be looking at closer to 300+W per GPU at the wall, which means closer to 280W per GPU from the PSU. This would mean you would need a 950W or higher (280x3=840+100=910). Realistically this means 1000+W PSU.

So some 3x 280x rigs can get away with a 750W PSU, while others will need 1000W PSU. It all depends on what you're doing, and how low you can undervolt.

[daserpent1]

280x draw upto 310W if not undervolted. And you can expect 260-280w if undervolted. But keep in mind, every card is not the same. So whie one may stay stable at a certain setting, other might not remain stable at the same setting as the other one.

[larem]

Our 5x 280x rig was pulling 1450W at the wall.

After we undervolted, that same rig was pulling 1250W.

Take away 100W for the system, and that's 1350W and 1150W for the GPUs.

That's 270W and 230W for each GPUs.

Those numbers were at the wall. These were on 80Plus Gold PSUs, on 110V, somewhere around 80-90% load, so the PSUs were ~88-89% efficient.

This means that the GPUs were pulling 240W (stock volts) and 205W (undervolted) from the PSU.

For 3 GPUs, you would need a 850W PSU (240x3=720+100=820). If you're undervolting, you would need a 750W (205x3=615+100=715).

If you're running high volts or massive OCing, then you can be looking at closer to 300+W per GPU at the wall, which means closer to 280W per GPU from the PSU. This would mean you would need a 950W or higher (280x3=840+100=910). Realistically this means 1000+W PSU.

So some 3x 280x rigs can get away with a 750W PSU, while others will need 1000W PSU. It all depends on what you're doing, and how low you can undervolt.

Also factor in the decreasing efficiency of the PSU. While a 750 may be fine right now as it pulls, say 710, in a month it may not be powerful enough anymore due to wear and tear.

[nskendrovic]

Hi all.
Im a beginer and i have 2 questions.
I have 1 Mbo with 2 gpus and 1 850w PSU.
I wana add 2 more gpu's...is it posible to just add another psu and conect it ionly to those 2 new gpu's or i have to upgrade to new biger psu and if so..would seasonic 1250 be enough?

Alos...as i mentioned i have 2 gpu's at the moment...1 is runing on 70C an other one on 90C..sometimes it gose til 94C...is that a problem or should i try undervolt them?

Ty in advance

[larem]

Hi all.
Im a beginer and i have 2 questions.
I have 1 Mbo with 2 gpus and 1 850w PSU.
I wana add 2 more gpu's...is it posible to just add another psu and conect it ionly to those 2 new gpu's or i have to upgrade to new biger psu and if so..would seasonic 1250 be enough?

Alos...as i mentioned i have 2 gpu's at the moment...1 is runing on 70C an other one on 90C..sometimes it gose til 94C...is that a problem or should i try undervolt them?

Ty in advance

On the PSUs, you can run more than one. A lot of people run rigs with 5 GPUs or more and use at least 2 PSUs. I don't know the technicals of doing that though.

[hyperionx]

No problems running several psus. I am now running three on my rig. Just make sure you run mobo/cpu and any powered risers on the same psu to avoid trouble. Basicly use one psu as main for everything except the pcie-power and then divide those up between them however you like.

Just remember that the gpus can grab as much as 75w from each x16 port which will be on the main psu.