I haven't seen much discussion on cooling here...If you have the card running inside a case with poor cooling, it will surely get hot. When I had a 7950 inside my gaming pc before the rest of my parts arrived, it would overheat and turn off. Cooling is much more of an issue with LTC mining vs BTC mining.
This is how my miner is set up right now. 3 Gigabyte 7950's spaced apart in a milk crate with a box fan blowing air in from outside. I live in San Diego so the outside air is pretty warm (I live inland, not by the coast).
http://farm8.staticflickr.com/7454/8730220674_0a0f6781fd.jpgThe cards run between 65 and 70 with my current config getting 1.773mhash/sec. I can crank it up an extra 150-200khash/sec by increasing the gpu-mem speed, but I like my fans running slower/quieter. I used to run with constant fan/gpu values and it would yield better temps at night (58-62*) when the outside air was cooler, but with the auto-fan and auto-gpu, it will keep it 70* or less and turn the fans down.
Here is my config:
{
"pools" : [
{
"url" : "POOL HERE",
"user" : USER NAME HERE",
"pass" : "PASSWORD HERE"
}
]
,
"intensity" : "20,20,20",
"vectors" : "1,1,1",
"worksize" : "256,256,256",
"kernel" : "scrypt,scrypt,scrypt",
"lookup-gap" : "2,2,2",
"thread-concurrency" : "24768,24768,24768",
"shaders" : "1792,1792,1792",
"gpu-engine" : "0-1000,0-1000,0-1000",
"gpu-fan" : "0-85,0-85,0-85",
"gpu-memclock" : "1000,1000,1000",
"gpu-memdiff" : "0,0,0",
"gpu-powertune" : "0,0,0",
"gpu-vddc" : "0.000,0.000,0.000",
"temp-cutoff" : "85,85,85",
"temp-overheat" : "80,80,80",
"temp-target" : "70,70,70",
"api-port" : "4028",
"auto-fan" : true,
"auto-gpu" : true,
"expiry" : "15",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"hotplug" : "5",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "15",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin"
}