hi,

i have that card and can't reach the hash rates from the hw comparison chart either. i'm maxing it out @ 710 though i'm not done with it yet..

try these:

-I 13 --gpu-fan 60 -w 256 -g 2 --lookup-gap 2 --thread-concurrency 11200 --gpu-engine 1030 --gpu-memclock 1500 --gpu-powertune -20

it seems that model is quite stuborn on the gpu-engine parameter. the sweet spot seems to be between 1020 and 1030. also i have to keep the fan running @ about 3000 constantly, seems to me that at 76° some sort of hardware safeguard locks in..

also try and lower your screen resolution and DON'T TOUCH THE RIG! EVER! most of the time i have an explorer running and that's it. no chrome, nothing else.. and maybe try some different pools.