I currently have Crucial Ballistix 12Gb of RAM composed of two RAM sticks. I cannot find any online that are at 6Gb. I had my computer built for me so I am not sure on the RAM setup. Is it bad if you possibly mix RAM kits. I'm looking about adding an additional 16Gb kit (8Gbx2) but im not sure if this will harm or disrupt my computer. Any help?