the mobo is an ASUS P6T, the regular one. and i havent checked the mfgs site. but the memories always worked as 12gb. one day it decided to only recognice 10gb. also, the memories are corsair 2gb x 3 kits of 1333mhz. i contacted asus and they told me there was nothing wrong on the mobo side since all ports were working (tested each one individually), they told me it was the CPU because the new core i7s come with integrated memory controllers. I switched my old C0 to a D0 and still same problem. I updated the bios and still same problem. now i dont know if is either the memories or the mobo itself causing the problem.