my offer 0.8 BTC

do you plan in the future to add some other mining option like x15 or you will keep up just with x11 and x13?

I use r9 290 tri-x for mining. I have 20 cards and i don't have any problem.
Try with diferent drivers, for my cards best is 13.12.
MSI Afterburner to set your card
and this is my bat file:
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
sgminer.exe -k x11mod -o stratum+tcp://amsterdam.eu.stratum.dedicatedpool.com:8001 --failover-only -u -p --gpu-fan 80,80 --gpu-engine 1020,1020 --gpu-memclock 1250,1250 --thread-concurrency 8193,8193 -I 18,18 -w 128,128 -g 4

If you are using MSI Afterburner delete this:--gpu-fan 80,80 --gpu-engine 1020,1020 --gpu-memclock 1250,1250
and you may want to play with thread concurrency, if you have more than 8gb ram you may try 24550 or even more.
And if you want to mine cryptonote than it's a diferent a lot.

stop scaming the Claymore, even he must go to vacation, it's August and he's probaly resting. and if you are smart enough make your own miner with 0% fee, until then stop crying about 5%.

i also dont agree with that that nvidia is ahead of amd. amd gpu's are true beast compared with nvidia for mining, but also amd has wery bad support of drivers, and the miner software are not optimized at all. Nist5 algoritm show's how far can amd gpus go, and that is from my opinion only 30, 40% of what amd (for example r9 290x) can do with performance.

Keep up the good work

Try to change the motherboard