My bat for 2x 7850:
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
del *.bin
Color 0A
sgminer -k marucoin -o stratum+tcp://maru.suprnova.cc:3131 -u username.worker -p password -I 15,15 --thread-concurrency 11264,11264 --lookup-gap 2,2 -w 256,256 --gpu-engine 1025,1025 --gpu-memclock 1300,1300 --gpu-powertune 20,20 --scan-time 5 --expiry 20 --gpu-fan 60,60
Total of 1.1 Mh/s
Yes I know you don't have to put values twice...the bat is from somewhere else.
You could probably push your 7850 to 1100 easy on x13. I got a BSOD when I did, but I'm heavily undervolted.