all of those megahashes are weighing down the aluminum!
Haha, yeah those cards are heavy... Especially the 7970s.
so even with liberal spacing for airflow you cannot get the XFX 7970s to break 700khash? hate xfx.
No, they're not overheating and there's no lack of power, that's a 1300 Watt PSU they're hooked up to.
Through some research I've found that 2 of my 7970s have an old BIOS on them that needs to be re-flashed. One of them seems to have the new version and I can get it to hash at ~700kh but the other ones drop to ~300 at those settings.
I'm not entirely sure that I am prepared to tackle reflashing my video cards because if I screw it up, my 450kh per card will go to 0 per card. Even though they aren't running optimally, they're still making some coin.