i work with 6950 and on smos and windows no problems.

in the smos it have a autostart option?
maybe you start the card manually and then the os autostarts a second cgminer and then crashes?

what temps your card is working?


this is the setup that i am using on windows
same on smos (i replace the values from this lines to the conf file on smos)
also very important on windows try to erase all the .bin files from the cgminer folder
and then start your new config.

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
.\cgminer-3.7.2-windows\cgminer.exe --scrypt -o stratum+tcp://*******:3333 -u user**** -p pass*** -I 17 -g 1 -w 256 --shaders 1536 --thread-concurrency 7042 --gpu-engine 850 --gpu-memclock 1300 --gpu-powertune 10 --gpu-fan 40-85

try this settings.

mine makes 765khs

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
.\cgminer-3.7.2-windows\cgminer.exe --scrypt -o stratum+tcp://*******com:3333 -u user**** -p pass* --intensity 13 -w 256 -g 2 --shaders 2048 --thread-concurrency 8191 --gpu-engine 1100 --gpu-memclock 1500 --gpu-powertune 20 --gpu-fan 68