So much great information in this thread! Here are my results and settings for getting about 5.5MH/s on a Windows 7 machine.
sgminer 4.1.0 - Started: [2014-05-26 16:42:22]
--------------------------------------------------------------------------------
(5s):5.353M (avg):5.352Mh/s | A:0 R:0 HW:0 WU:0.077/m
ST: 1 SS: 0 NB: 1 LW: 378 GF: 0 RF: 0
Connected to Pool 0 (stratum) diff 0.001 as user xxxxxxxxxxx
Block: 21143457... Diff:623 Started: [16:42:22] Best share: 0.207
--------------------------------------------------------------------------------
[P]ool management [G]PU management [S]ettings [D]isplay options [Q]uit
GPU 0: 70.5C 3570RPM | 1.864M/1.872Mh/s | R: 0.0% HW:0 WU:0.025/m I:20
GPU 1: 64.0C 2282RPM | 2.066M/2.098Mh/s | R: 0.0% HW:0 WU:0.032/m I:20
GPU 2: 60.0C 1627RPM | 1.464M/1.459Mh/s | R: 0.0% HW:0 WU:0.021/m I:18
--------------------------------------------------------------------------------
[16:46:34] Accepted 0118f62e Diff 0.004/0.001 GPU 1
[16:46:34] Accepted 81fe0c91 Diff 0.008/0.001 GPU 0
[16:46:35] Accepted 4b7c174c Diff 0.013/0.001 GPU 0
[16:46:36] Accepted 8da9afb0 Diff 0.007/0.001 GPU 2
[16:46:36] Accepted 038da71b Diff 0.001/0.001 GPU 0
[16:46:37] Accepted 010f4a62 Diff 0.004/0.001 GPU 1
[16:46:38] Accepted df3a953c Diff 0.004/0.001 GPU 1
[16:46:39] Accepted fed8423e Diff 0.004/0.001 GPU 0
[16:46:40] Accepted 039a8191 Diff 0.001/0.001 GPU 0
[16:46:40] Accepted 0192e7a7 Diff 0.002/0.001 GPU 2
[16:46:41] Accepted 0280ef55 Diff 0.002/0.001 GPU 2
[16:46:41] Accepted e9110510 Diff 0.004/0.001 GPU 2
GPU0 = 6950
GPU1 = 270x
GPU2 = 7850
]
,
"device" : "0,1,2",
"gpu-threads" : "2,2,1",
"worksize" : "128,128,256",
"intensity" : "20,20,18",
"lookup-gap" : "2,2,2",
"thread-concurrency" : "8192,8192,5120",
"temp-cutoff" : "90,90,90",
"kernel" : "x11mod",
"vectors" : "1",
"gpu-platform" : "0",
"shaders" : "1280,1280,1024",
"kernel-path" : "/usr/local/bin"
}