Use this on your config:
"intensity" : "18",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"thread-concurrency" : "21712",
"shaders" : "1792",
"gpu-engine" : "1050",
"gpu-fan" : "60-100",
"gpu-memclock" : "1500",
"gpu-powertune" : "20",
"gpu-threads" : "1",
"temp-cutoff" : "74",
"temp-overheat" : "70",
"temp-target" : "66",
What card and miner sw you're using?
XFX79503gb (not a doubleD, but same PCB)
BFGMiner (fwiw 8gb DDR3pc1600)
Using those setttings gets me ~28kh/s
If i remove the --lookup-gap then i get 240kh/s Intensity was too low *facepalm* somehow i missed the intensity setting when copying the config
Using the above settings im now running at 512kh/s (without the --lookup-gap)