ASRock 990FX Extreme3 ATX AM3+/AM3 Motherboard with G.Skill Sniper DDR3 8 GB (2 x 4 GB) PC RAM (F3-12800CL9D-8GBSR) in ram support list it is not showing it's name what to do
It just means that ASRock did not test it with with the motherboard (they can't test everything). The memory is 1.5 volt with standard timings so there is no reason it should not work.