AMD CrossFire: Load on the PSU

[JamesLangley]

Hey guys. I am looking at getting a new rig together and am brand new to the idea of SLI or CrossFire. I'm looking at the possibility of going for a quad crossfire setup using a set of Gigabyte Radeon 7770 OCs. The problem I am seeing here is the rated load on the PSU is massive - a whopping 400W each card. That means that with the CPU (AMD 8-Core 8150 @ 150W) I am sitting at 1850W power requirement already, without taking into consideration the watercooled aftermarket cooler and 1 x 140mm and 2 x 200mm fans in the new case.

Am I looking at this wrong, or is there some way around this that I am not seeing? I cannot see any PSU on the market over around 1500-1600W.

 

[JamesLangley]

I think I have found the answer from google (took a while though lol).

Is this the minimum power supply to run each card? A benchtest I found on a website mentioned it uses 85-90W under full load, so an 850 watt PSU would run this fine in consideration with my other power requirements.

Is this correct?

 

[samuelspark]

Lolwuuuuuuut. Each card does not take 400w. It's 400w for the fulll system. With a 550w you'd be more than able to run 7770 CF.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817182200&Tpk=rosewill%20rg630
^ good cheap psu with more than enough power.

BTW, you can't crossfire four 7770. There's not enough CF bridge connectors. Max is two. And after 2 the scaling of each card decreases dramatically. (+AMD CPU's are bad)

 

[JamesLangley]

Cheers, yea, I kind of freaked lol. I do know some cards can take up to 150 with an extra plugin from the PSU.

Can't use newegg, as I'm in australia lol. Been looking at a Corsair 650W Modular PSU though.

 

[samuelspark]

I would wait a bit for the Piledriver CPU's to come out. And get a 550w+ PSU.

 

[JamesLangley]

Best answer selected by JamesLangley.

 

[JamesLangley]

Thinking I might just bite the bullet and go for a Intel 3770 instead.

 

[samuelspark]

Good choice.

 

[bloc97]

Yea, I have myself a HD 7770, and I can confirm that it works under full load in a system with a PSU of 250W.

-Bloc97