The same with RAM, mb have serious problems with memory at FSB400 and 4 RAM modules. My 2*1GB Hynix'05 work best with frequirences upto 900MHz, I buy another 2*1GB labeled Hynix'07 , they can reach even 1GHz, but all 4 modules can't work at even nominal 800MHz, then FSB is 400(1600), only at lower 600MHz multiplier they all can work, so I returned new modules back.