My xfx 290 is running at 9.7mh/s stock 1000mhz with this config  -p x -w 64 -I 26 --thread-concurrency 27400 --lookup-gap 2 --gpu-threads 1
i have 2 xfx 290x's that im still tweaking but they are only going at 9.6mh/s each so far