Hello,
I have a problem with my rig. Just testing 2x7970 configuration now (waiting for other mb to plug in more cards). I was trying bamt and xubuntu. I was also trying cgminer (many versions) and diablominter.
The problem is when i start mining on two cards the hash rate drops by a half. Eg. when i dont use command DISPLAY=:0 i have 650Mhash on one card. But when i use it i have about 300Mhash each (so overall it reamains the same).
What might be the problem? I tried many things, i have newest drivers on xubuntu now (from repository). Everything works fine, just hash rate drops.
Is it possible that my internet access is blocking me? I have just 0,5Mb connection to the internet and there is already one mining ring working (4x5830).
I am personally mining one of the alternate coins. However, I've got a very similar setup.
2x 7970's
1x 1000W PSU
Ubuntu 12.04 Desktop (I actually run xubuntu as my VNC X server
Catalyst 13.1 (with the included SDK)
I've not run into any significant problems, other than heat, with the configuration. I'd suggest you uninstall the drivers that were available from the stock repositories, and download directly from AMD's site.