-I 13 -g 2 -w 256 --gpu-memclock 1500 --gpu-engine 1080 --gpu-powertune -20 --thread-concurrency 8192 --auto-fan --gpu-fan 30-75 --temp-cutoff 90 --temp-overheat 85 --temp-target 72
Don't use Crossfire. Undervolt to 1100 (1.1V) in Trixx for cool temps and 740kh/s.