@SomeoneWeird - Yes, I managed to install it. I have this system with Three ATI 6990s, Approximately 2.1 Ghash/s
https://en.bitcoin.it/wiki/Mining_rig, the only difference is the motherboard where I got a Crosshair IV Formula (Asus) instead, same brand as the 3x6990.
My system is Ubuntu 11.04 64 bit and I followed the great guide found elsewhere in this forum.
The problem I'm getting is with underclocking, because from the three cards, only GPUs from the middle card remain at workable temperatures (below 85 C) The top and bottom card jump above 100 C in matter of seconds and quickly enough, the system freezes. I'm trying to control it via SSH, because I'm in another country.
After installing AMDOverdriveCtrl, I had my buddy run the utility GUI and the settings we set for low - med - high are all identical, that is GPU 850Mhz, MEM 300 Mhz.
Via SSH, I run the AMDOverdrive -b -i 0 xxx.ovdr and it runs correctly, so I do the same for the other 5 devices as well.
After that, I check aticonfig --odgc --adapter=all and it shows me the Current Peaks I had in the xxx.ovdr profile, the configurable peak range is also correct, but the current clocks are beyond the 300 Mhz and state 1250 Mhz.
So I turn aticonfig --od on and aticonfig --od-setclocks=830,300 --adapter=all and it does chance the Current Peak for all, but Current Clocks remain unchanged.
It's a pain in the ass because I can't tweak it and hard reset it as needed, due to the fact that the rig is actually half a world away and my buddy is most of the time out of his office, where the rig is. To make matters worse, his Internet connection at the moment is very basic, so there's no static IP, so everytime something goes wrong and I can remotely reboot to prevent some crazy fire while nobody is in that office, I can't log back in because it changed the freaking IP. LOL
So, here I am, mining with the two GPUs from the card in the middle. I switched to Eligius so that I don't have to Add the new IP to the Whitelist of Slush after every reboot.
If any of the more seasoned miners cares to help, I'm more than willing to share some bitcoins once the rig starts "showing me the btcs".
Cheers!