Memory Controller Issues with X48 Motherboards Hi Friend, You are absolutely right on the memory part. I too have the same situation in my Rampage Formula X48. Mine is a Mushkin Blackline DDR2 1066. You just cannot run all the 4 modules in 1066 Mhz as it loads the NB. I had a long chat with Mushkin Sean and he helped me a lot to tweak the settings and finally i decided to down clock the memory. Presently running the 4 sticks at DDR2 1003 and is stable with MEMTEST and OCCT. There is no other way and the BIOS on the X48 boards doesn't give us the much needed tweak settings for Memory to run the system stable. We have to live with it. On the other hand, if you are happy with only 2 sticks, the system is stable at DDR2 1066 Cheers !