I didn't select raptr - I hate to be patronized which graphics quality setting I have to choose… I know which options I want to enable… ;-) So I didn't have installed it.
Best opinion about raptr, EVER !!!
I played a bit with X-fire disabled and it seeme to get rid of the problem but I didn't do it long
You can run synthetic benchmarks (like unigine valley/ heaven) or in-game benchmarks (like batman arkham origins) in crossfirex/ without crossfirex and test that theory.
Assuming you don't have artifacts because overheating problems (check with afterburner), that is. Is one card right on top of the other inside your pc (pcie slots too near to allow proper airflow) ?
gigabyte X58A-UD3R rev.2, core i7 975 3.9ghz (stock voltage), windows 8.1 64-bit, corsair 12gb DDR3 1600mhz 7-7-7-20 RAM, xfx HD 5970 + gigabyte HD 5970 (950mhz/ 1100mhz), coolermaster ultimate 900w PSU.
amd catalyst 14.12 Omega Driver