Hi, may I ask what is the config for your 7850? Mine is only 10MHs.

Sure, here is what I use. (I simplified it by removing multiple pools I use normally)
setx GPU_MAX_ALLOC_PERCENT 100
C:\Mining\cgminer-heavy\cgminer.exe --heavy --vote 1 -o stratum+tcp://hvcpool.1gh.com:5333 -u
-p VIP -u jakiman.roompc -p x -I 4 -g 1 -w 64I use Trixx to overclock it to following also. (Probably what makes the diff)
Core: 1180Mhz
Mem: 1250Mhz
VDDC: 1210mv