- 855 GPU clock is slow for that card. Stock core is 925, boost clock is 975. It should easily run 925 or higher.
- Thread concurrency should be more like 15232
- Intensity should be between 16-18
- You may also want to add haders 1536 as well to see if that helps, as cgminer might not be detecting the right amount of shaders for the card
Try fixing those.
Set a few of these, this one produces around 310 at 1100 core, 1500 memory.
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer.exe" --scrypt -u x. -p x -o stratum+tcp://pool1.us.multipool.us:7777 -d 0 -w 256 -v 1 -I 18 -g 1 -l 2 --thread-concurrency 15232 --shaders 1536
This gets me around 360 with same core and memory. Backing down to 700-800 I might get up to 380
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer.exe" --scrypt -u x.x -p x -o stratum+tcp://pool1.us.multipool.us:7777 --gpu-platform 0 -d 0 -w 256 -v 1 -I 12 -g 2 -l 1 --thread-concurrency 8192