Is G. Skill Ripjaws X Series (4x4GB) DDR3 1333Mhz compatible with the ASRock 970 Extreme4 motherboard. I've checked the charts and it doesn't seem to be on there. But I'm not entirely sure. I'm working on a full build for a computer and am trying to make sure all parts are compatible before purchasing. If it is not compatible then would you leave recommendations please?