When I do -i 6 on my 7950's, it says there is not enough ram and it reduces it to 5! What SOL/s are you getting on your 7950s?
Well I have managed about 260 (-i 5) at 950/1450/1.05v, last claymore zec miner.
I'm getting around the same hashrate (-i 5) on my 7950's. I have not done the undervolting yet. Will it make a lot of difference to power/heat?