here is my setup
4x sapphire cards, and 2 asus dc2 cards.
https://i.imgur.com/a3IiFhY.png2 systems tho, 3 gpus each. 1000watt for each.
1 is amd, with 8gb ram, the other is cheap intel 1155 also with 8gb. (getting a thread conc error with lower ram)
even with those temps, i cannot go higher, because after a few hours at least 1 of them dies and cgminer cocks up and crashes.
the gpus are running 1100-1130, mem is 1800-1820
no voltage increase. and still no risers,
I did notice that putting a fan on top helped alot with temps, and so did an exhaust fan at the back of the cards (it pulls air away from the cards)
settings are close to these ( i often have to adjust the gpu/mem)
"intensity" : "13,13,13",
"vectors" : "1,1,1",
"worksize" : "256,256,256",
"kernel" : "scrypt,scrypt,scrypt",
"lookup-gap" : "2,2,2",
"thread-concurrency" : "8192,8192,8192",
"gpu-engine" : "0-1135,0-1100,0-1135",
"gpu-memclock" : "1815,1795,1815",
"gpu-powertune" : "20,20,20",
"gpu-fan" : "0-100,0-100,0-100",
"api-mcast-port" : "4028",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "2",
"hotplug" : "5",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "10",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin"