thx
This is my config :
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer.exe -u -p -o -I 15
cgminer.exe --scrypt -o stratum+tcp://east1.us.stratum.dedicatedpool.com:3386 -u XXXXXXXXXXX -p XXXXXXXX -I 15,15 -w 256,256 -g 1 --thread-concurrency 8193,8193 --lookup-gap 2,2 --gpu-engine 1100,1100 --gpu-memclock 1500,1500 --auto-fan --temp-target 67,67
Good configs r9 270x - 475k/hs - _http://www.smos-linux.org/configs/
Now it's perfect thx for your help.Regards.