Hey guys,
I have a sapphire 7970 and I just cant get this thing above 600kh/s    Ive tried everything i can think of. First person that suggests something that gets my 7970 over 650kh/s ill give you 1000 dogecoins!!  

I know this card has more to give, whenever ive tuned other cards to their max you start to notice abit of system lag, but Ive never experienced any lag with my 7970.

as soon as I change any of the following my kh/s drops alot.
higher thread concurrency,
lower thread concurrency,
more than 1 thread,
higher intensity,
lower intensity,
increase memory clock,
increase gpu clock,

temps are always good and VRM's arent getting hot either

im using CGminer 3.7.2 on windows 7 x64 sp1

currant settings:
"intensity" : "13",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"thread-concurrency" : "20400",
"shaders" : "0",
"gpu-engine" : "1150",
"gpu-fan" : "65-65",
"gpu-memclock" : "1375",
"gpu-memdiff" : "0",
"gpu-powertune" : "20",
"gpu-vddc" : "0.000",
"temp-cutoff" : "92",
"temp-overheat" : "86",
"temp-target" : "80",
"api-mcast-port" : "4028",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"hotplug" : "5",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "30",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin"





Any help tuning this would be much appreciated!!!