Crossfire - Power comsumption on a 7970

[krishy]

Hi,

I have just bought 2 7970 powercolor cards, and shall be using them in crossfire. I am new to crossfire, and have only used a 6950 in the past.

I just wanted to know, with my setup, will 750w from a 80+ PSU suffice?

I am using a 3570k at 4.2ghz, and im hoping to overclock the 7970's too, would this be safe with 750w?


Also, i just wanted to know, if i was playing a gpu-friendly game like GTA San Andreas, would it still use both cards? Or does the second card only become active when needed? (Im scared of energy bills)

Thanks

 

[swilczak]

You should get a 1000 watt PSU if you want to be safe. The 7970 uses a lot of power, and with two of them you are cutting it real close with a 750 watt. Personally I don't think you will be safe with that setup. You can go to AMD CCC and look all of the application profiles to see if that game is listed. If it is then the game will use both GPU's.