Quote from: Toschi on May 18, 2013, 11:07:06 PM

I have the Powercolor AX7950 GPUs with a 1600W LEPA PSU and the Gigabyte 990FX UD-5 motherboard. With a Kill-A-Watt hooked up to it, I see a power draw on it of about 1400W. Maybe that was when I had powertune at +20 on it though? I'm redoing that board now as we speak (bringing it up to Windows 8 instead of Windows 7) and won't be having powertune on it this next time. I'll report back once it is up and running. Swapping out standard risers for powered risers to see if the kH/s goes up some with non-powertuned settings. Then I'll attempt to add a 6th card into the PCI-e 1x slot (I have a 1x->x16 riser) if all goes well.

This milk crate is getting tight on space! :p

I highly advise against using Windows 8. Setting up AMD Drivers on Windows 8 was hell for me and my friends on various systems. We couldn't get it to recognize 3 7950s on one system and we tried the 11.12, 12.8, 13.1, and 13.4 drivers and every time it just jacked the display and didnt work each time. We probably missed something required, but we reverted to W7 and Linux on the systems and they work fine.

Powered risers will ensure that you have the highest possible hashrate though when using a motherboard with more than 4 GPUs. My friends do out safety reasons though (fire prevention).