1. Disable crossfire and remove the plug
2. Run as root or sudo "aticonfig -f --initial --adapter=all"
3. reboot
4. In a new terminal run "export DISPLAY=:0"
5. Then run "cgminer --gpu-memclock 300 --gpu-fan 100 --gpu-engine 900 --gpu-vddc 1.1625 -o
http://xxx.xxx -u user -p pass -I 9"
That should get you over 400mh per card as a baseline. Hit "G" to confirm clocks and voltage. If it's stable, adjust the gpu-engine up by 5-10 mhz at a time (or voltage down, fan, etc) until you are happy with temp and perf. You may add --cpu-threads 1 if you have the max cpu bug to isolate to a core.