Ah...you got another option with more specific experience to your cards. -
OPCurrently mining ETH but system is really unstable while using r9 fury x in combo with r9 290. Keeps having Temp control errors or OpenclCALL errors on the fury x. Solo mining with fury is no problem, strange.
Hashrates eth 31 on stock clocks max is 36 ( 1200mhz core )545 ram
Equihash 490 stock clocks and max 510.
these errors are also on stock clocks so its not about my overclock thats unstable.
r9 290
Eth 30 (1040mhz core 1250mhz mem)
Equihash 330 sols/s
Buddy, I always liked R9 owner, that's really cool. I have a few R9 series (290,290X,390,390x) and 16.9.2 giving me the best performance on those all card.
Another story - my friend (that I mentioned above) use hybrid driver (may I need to ask him back which driver source that used) to combine Fury with R9 390 in one rig.