r9-270 on sgminer/nfactor branch: 254/254/245 kH

sgminer.conf

"kernel" : "ckolivas",
"nfactor" : "11",
"failover-only" : true,
"verbose" : true,
"xintensity" : "4,4,4",
"gpu-threads" : "2,2,2",
"worksize" : "256,256,256",
"thread-concurrency" : "6143,6143,6143",
"gpu-engine" : "800-1160,800-1160,800-1125",
"gpu-fan" : "60-90,60-90,65-90",
"gpu-memclock" : "1500,1500,1475",
"gpu-powertune" : "20,20,20",
"temp-cutoff" : "90",
"temp-overheat" : "80",
"temp-target" : "75",
"temp-hysteresis" : "3",
"auto-fan" : true,
"auto-gpu" : true,