I was planning on OC'ing but probably only to 4.5; don't plan on any higher than that. I haven't finished the build yet, still waiting on some parts. I just happened to see a deal for the 2x2GB@1.5V and thought about getting it. How do you go about setting the DRAM Frequency, CAS Timings and DRAM Voltage per rated spec. when you mix match (don't think you can use XMP, BIOS / AI Overclock Tuner -> XMP for this)?