Bitcoin Forum

Just tested two 5870 on Ubuntu with cgminer and crossfire (can't detect two GPU without using crossfire), but I am only having about 600 mhash/s .  Wonder what is the best commands for it to maximize the hashes?

Change the intensity to 9 or so. Never used crossfire. I was able to use my second card without a VGA dummy plug in Win7. But using one is better for me. Now i can change the settings the way i want. That was not possible before.

Prob is without cross fire, my cgminer can only recognize 1 GPU using Ubuntu Linux, will Windows recognize two without cross fire?

It should.

600MH? Thats weird. Its too much a single card and not enough for two.
And you shouldnt have to use crossfire

I think 600 MH/s is two in crossfire

Yeap it is two in cross fire, or should I be using windows and guiminer?

You can stick with cgminer in windows. Works well.

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.

Try to get it working at default gpu clock and voltage before tinkering with those.

As coretechs said "aticonfig -f --initial --adapter=all" is probably what was missing. It sounds like you only had one GPU configured and the second is limping along purely by being attached by crossfire. You shouldn't need crossfire.

I think I will reinstall, any recommendations?  Ubuntu 11.10 or 10.4?

11.04 :P
See my sig
(and don't update it to 11.10 - not needed and not enough space if you use a USB to run updates)

Thanks a million, your sig is just what I need!