command to run cgminer.
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer --scrypt -I 19 -g 1 -w 256 --thread-concurrency 22400 --gpu-engine 1050g --gpu-memclock 1475 --gpu-vddc 1.087 --temp-target 78 --auto-fan -o stratum+tcp://www.weloveltc.com:3333 -u username -p pwd --failover-only -o stratum+tcp://us2.stratum.ltc.nushor.net:3333 -u username -p pwd
Almost all 7950's will run steady at 600kh/s-625kh/s for extended periods of time with "--gpu-engine 1150g --gpu-memclock 1250 -g 1 --thread-concurrency 19712 " (just try adjusting the -I setting...starting at 16 until you overheat your target)
Personally I wouldn't use "--auto-fan". I would set it at 85% - 90% and play with the setting to keep it at or near your desired temperature.
Also for some reason, the 7950 likes powertune. Try 10 or 20 to fine tune your GPU.