I optiminer miner does not work, 2 cards do not want to engage in mining that can be 
With optiminer there's always a card hanging and I don't want to babysit rigs. CM 11.1 no problems!
Optiminer 1.6 has been rock solid for days on my Ubuntu 14.04/fglrx box. One of my R9 380's was hanging at 1550 memory clock, but has been fine at 1500.
So if optiminer stresses the hardware more than CM, the issue is not with optiminer its your overclocking.