Radeon 5870: CGMiner 3.7.2 Linux slower than Win 7?

Because running out of windows licenses, i deceided to run my first linux rig (completely new to linux).
For testing i'm running a Radeon 5870 which makes stable 400kh/s under win 7 x64 Catalyst 13.12 (no hw errors, and very low rejected) using following config:

"intensity" : "18",
"shaders" : "1600",
"thread-concurrency" : "9600",
"vectors" : "1",
"worksize" : "256"
"gpu-engine" : "850",
"gpu-memclock" : "1200",
"gpu-vddc" : "0.000",
"lookup-gap" : "0",

Trying Bams 1.3, 1.4, 1.5 and unsing different guides/settings from the web, cgminer always stuck at ~300 kh/s without hw-errors.
After changes in the cgminer.conf i always start cgminer with cgminer.sh :

export GPU_USE_SYNC_OBJECTS=1
export GPU_MAX_ALLOC_PERCENT=100
export DISPLAY=:0
find *.bin -delete
sleep 5
./cgminer

Also tried catalyst 13.12 but no improvement...
Is that a driver issue (what i guess) or a settings issue?

Topic: Radeon 5870: CGMiner 3.7.2 Linux slower than Win 7? (Read 587 times)