Absolutely, I have 5 msi 7790s on claymore v8 right now, 3 solo and 2 on ypool. They are each getting ~64000 4ch/hr, and estimated 1.95 CPD. With 3 of them solo for the past 40 hours or so I've mined 2 blocks so far. Not officially supported but they work more than well IMO. My clocks are set to 1050/1000
I'm using msi too, just tried with default clocks for 2 hours, I'm getting 69000 4ch/hr, 1.98 CPD and still crawling up.
set the memory down not affecting mining speed?