Try the 7950 with a thread concurrency of 14336.
That let me go all the way up to I = 20.
I'm also using CPU = 900 MEM = 1250 to go with a lower voltage level.
@gsupp what is your voltage on that card?
tried a TC of 14336 at I 20, starts giving HW errors. Ive been playing around with the setup for the last 4 hrs, the best ive got so far is 560 on I 18 and a TC of 20400. Interestingly using a TC of either 20399 or 20401 lowers my hash rate by 40khs.
stock voltage on both cards
7950 1.075
7970 1.175
Got the 7970 to 591khs with the same TC as the 7950 (TC 20400), I find that unusual. the 7970 does not like running more than 1 thread, and only runs on intensity 13, more or less intensity regardless of other setting always results in a poor hash rate so far.
This is going to make me crazy!!! XD