I spoke to a tech at MSI last week regarding a 533fsb cpu on my 845 Ultra- he said that although it does not "officially"support the 533fsb, in theory, it should work, because the 533fsb setting is in the bios. I plan on picking up a 2.4, since the prices have dropped so much, in the last few days. If it dosen`t work, I`ll post again.