Quote from: Eastwind on September 27, 2013, 07:47:07 AM

I run my 7950 at 13 intensity with 2 GPU threads to reduce the rejected shares. It is 15% slower than 19 intensity with 1 GPU thread.

I've dropped the intensity on all of my cards down to 18 (5850's, 5870's, 6950's and 7950's) running 1 GPU thread and the rejects are around 4-5% If I put them any higher the rejects jump to 12-15%.

Quote from: Epeus on September 26, 2013, 08:28:00 PM

Sorry to report I switched the 6990 rig over to a LTC pool.
Reason : rejects all over the place.
The 7970 rig is still happy moooo-ing away however.
As I mentioned before, the 6990 on I 19 setting does not like the low diff coins.
The 7970's on I 13 dont care about it.
Same mobo/os/miner etc.
It has nothing to do with the pool.
Perhaps I'd better sell the 6990's and buy back 7970 instead....

Try lowering the diff on your 6990, even try multiple threads on a lower intesity. Yes you get a slightly lower hashrate (difference on my cards is like 5-10kh/s) but you get less stales and a higher return, at-least that's what I have found anyway.