16384 concurrency, 256worksize. Gigabyte WF3, Voltage locked.
Before anyone asks, it runs those settings 24/7. i forgot to take the SS before restarting cgminer.
What about clock speeds?
i have my 7870 tahiti le which is basically a 7900 chip... setting worksize from 128 to 256 greatly increased my hash rate per second. I would say the increase was by about 10% give or take. Went from 450 to 505-512mh/s