Hi, i have a problem.
If i set the thread concurrency over 24700 the miner doesn t mine! 

I have a r9 290x, windows 7, cpu sempron 145

With this setup  get 880khs:
-I 20 -g 1 --thread-concurrency --lookup-gap 2 --gpu-powertune 30   

 gpu clock 938  memory clock 1500


can someone help me??  Embarrassed

thx