I have 10 rigs + other 3 rigs friend of mine, all of them are 4xGPU, 280x (Sapphire, Asus) 7970 (Sapphire), all sorts of cards combined,
but I never had a problem with ver. 3.x, which is most people stating in here.
For tweaking I'm using MSI afterburner, if you have low hashrates and clocks are jumping,
just try to give more volts.
I did not made any other adjustments.
And as well I'm mining with 2-3 threads with CPU on those rigs.
It's running full throttle and nothing is lagging, everything is running stable.
So I can say there is no problem at all with Claymore miner.
I would love to try any method to get this working. What voltage increase should I attempt?
I also would like to note that I do not have problems with the clock speeds bouncing around. Just lower than usual hashrate.
~360 h/s
edit: If you could check to see what memory type (elpida?) your cards run that would help me out too.