How large PSU for 7970 CrossFire?

[RaistlinZ]

I currently have a Corsair HX750 PSU. I'm sure 7970 CrossFire would be pushing it with this, but how large of a PSU would I need?

 

[RavenSEAL]

You should be fine but I guess if you REALLY wanna be safe, around 900w should be the mark.

 

[Satire]

7970 requires less power than a 570, so CF 7970 on corsair HX 750w will work fine

 

[lehtv]

Will work fine on a 750W corsair. 200W per card + 200W for the rest of the system (OC'd i7) ~ 600W/750W ~ 80% at full system load which is fine. Corsairs are designed to handle that sort of load without issues.

 

[BoomerD]

http://www.guru3d.com/article/amd-radeon-hd-7970-review/8

Our test system is based on a power hungry Core i7 965 / X58 system. This setup is overclocked to 3.75 GHz. Next to that we have energy saving functions disabled for this motherboard and processor (to ensure consistent benchmark results). On average we are using roughly 50 to 100 Watts more than a standard PC due to higher CPU clock settings, water-cooling, additional cold cathode lights etc.

We'll be calculating the GPU power consumption here, not the total PC power consumption.

Measured power consumption

System in IDLE = 163W
System Wattage with GPU in FULL Stress = 355W
Difference (GPU load) = 192W
Add average IDLE wattage ~3W
Subjective obtained GPU power consumption = ~ 195 Watts
Mind you that the system wattage is measured at the wall socket.

 

[Elfear]

As long as you're not overclocking the cards much you should be fine. I was getting random shut-downs with the parts in my sig (cards were overclocked) on a quality 800W PSU. That happened playing Starcraft II and sometimes running through the STALKER: COP benchmark. My Kill-O-Watt indicated 770W at the wallplate. A new 1000W PSU solved the issue.

 

[DooKey]

If you are going to OC and OV the cards and run them 100% folding or something like that and run your CPU 100% folding as well then I'd go at least 850w. If you are just gaming then your 750 will be just fine.