Miners dogpiling on one device I've built a mining rig running Ubuntu 11.10 with 3 Radeon 6850 GPUs.

When I run ./poclbm.py without any arguments, it returns the list of available devices as...

[0] Barts
[1] Barts
[2] Barts
[3] AMD Sempron(tm) 145 Processor


giving me the (possibly erroneous) idea that I seem to have the drivers setup correctly.

When I start up one miner and pass the argument to use device 0, the hash rate is reported at slightly over 200 Mhash/sec. However, when I start up another pointed at device 1 in a separate term window, the hash rate for both is reported at around 100 Mhash/sec. And when I fire up the third miner and point it at device 2, then all three miners report their rate at around 60-70 Mhash/sec.

This suggests to me that the miners are not honoring the device argument that I'm passing and all dogpiling on one of the devices (probably the freckle faced red-headed one). 

This happens with both m0mchil's poclbm and with PhoenixMiner.  Below are the arugments I'm passing to each...

./poclbm.py http://username.worker:pw@host.com:port -d 1 -v

./phoenix.py -u http://username.worker:pw@host.com:port -k phatk2 DEVICE=2 VECTORS BFI_INT


Any ideas what I might be doing, or have done, wrong?
You could check the temperature on the devices, the one active should be running much hotter than the others.

If they're all running hot the bottleneck is elsewhere (CPU or memory/bandwidth). If none of them are running hot you've bought one hell of a CPU to get 200Mhash.

Else it's advisable to check whether or not you can use the non-default videocard at all.

I'm afraid I lack the videocards to test this myself :)