I have 2 x Sapphire 7950 Boost cards running on Windows. I can only get them running stable on intensity 16 using CGMiner. Anything above that and the whole system freezes up (screen stays on but everything else is unresponsive).
Previously I had them on linux running BAMT, and I could get them running fine on intensity 18/19 for longer.
So I'm positive the cards should be able to handle greater than intensity 16, and I have two more PC's with just a single card in running around 600 KH/s, so I know they can.
What could be causing the system to freeze? Is it the cards or could it be drivers etc? Theyr'e only clocked at 1000/1250, with 24768 for thread-concurrency. Nothing over the top, and settings which are fine on the two single card PC's.
Here's my config file:
"kernel" : "scrypt",
"scrypt" : true,
"no-submit-stale" : true,
"temp-cutoff" : "85,85",
"temp-overheat" : "80,80",
"temp-target" : "70,70",
"auto-fan" : true,
"api-listen" : true,
"api-port" : "4028,4028",
"intensity" : "16,16",
"vectors" : "1,1",
"worksize" : "256,256",
"lookup-gap" : "2,2",
"thread-concurrency": "24768,24768",
"gpu-engine" : "1000,1000",
"gpu-fan" : "0-90,0-90",
"gpu-memclock" : "1250,1250",
"gpu-memdiff" : "0,0",
"gpu-powertune" : "0,0",
"gpu-vddc" : "0.000,0.000",
"expiry" : "30",
"gpu-dyninterval" : "7",
"gpu-thread" : "1",
"sharethreads" : "32",
"log" : "5",
"queue" : "1",
"retry-pause" : "5",
"scan-time" : "30",
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin"