My experience is the same as restless. On my two gigabyte 270OC, 9.7 is still the best.
11.0
-h 448 -dmem 1 (11.0 default) - OpenCL hang.
-h 512 -dmem 0 - 840h/s
-h 256 -dmem 1 - 810h/s
9.7
-h 512 (default) - 855-860h/s
Similar with me. I have an R9 Nano 4GB, Win 7 x64 OS, 17.12.1 Adrenaline drivers...
V10.2 = 865H/s
V10.2 -h 920 = 875H/s
V11 =
465H/s (dmem autoselection reports 1)
V11 -dmem 0 = 815H/s (uses less than 2GB of VRAM)
V11 -dmem 0 -h 990 = 865H/s (uses around 2.1GB of VRAM, any other -h value reports a lower hash rate)
Weird. Back to v10.2 for the time being, I guess...