I try again:
My trouble:
Sapphire 280x Vapor-x (Elpida Memory) 3GB, undervolted to 1.087, hashrate only avg. 70 khash/s
My system configuration:
Win 8.1 64bit Pro
AsRock H81 Pro BTC
4 GB Ram
2x MSI 270 Gaming 2gb (undervolted to 1.100 = avg. 87 khash/s)
2x Sapphire 280x Vapor-X
My config
"scrypt-jane" : true,
"sj-nfmin" : "4",
"sj-nfmax" : "30",
"sj-time" : "1388361600",
"api-listen" : true,
"auto-fan" : true,
"failover-only" : true,
"gpu-fan" : "30-85",
"gpu-threads" : "1,1,2,2",
"intensity" : "16,16,12,12",
"gpu-engine" : "1000,1000,1050,1050",
"gpu-memclock" : "1250,1250,1500,1500",
"gpu-powertune" : "0,0,20,20",
"kernel" : "scrypt-jane",
"kernel-path" : "/usr/local/bin",
"no-pool-disable" : true,
"temp-cutoff" : "84",
"temp-hysteresis" : "3",
"temp-target" : "72",
"worksize" : "256,256,256,256",
"thread-concurrency" : "22336,22336,16384,16384",
"lookup-gap": "2,2,2,2",
"queue" : "0",
"scan-time" : "1",
0 = 270, 1 = 270, 2 = 280x, 3 = 280x
I tried change TC, lookup-gap,gpu-threads, change virtual memory, add + 4 GB ram nothing helped, same hashrate.
But:
If I plug only one 280x without any other card, hashrate was fine 135-140 khash/s, if i plug second 280x hashrate fall to 75 khash.
If i change intensity up +13, hashrate changed to 135-140 but with many HW errors.
Thanks for any ideas. Sry for a terrible english
Any Idea
