Several people have successfully "upgraded" their ASUS P3S333 (which has the SIS645 chipset) with the P4S533 BIOS (for the SIS645DX chipset) to get more divider ratios. The process,however,is NOT reversable. The BIOS is trashed if reversal is attempted. I really wish the SD7-533 had a 4-6-2-1 ratio to get a 133Mhz FSB-200MhzDDR-66MhzAGP-33MhzPCI divisor combo. (4-5-2-1 is the best it has now). What do you think the chances are of successfully "upgrading" to 4-6-2-1 with the SA7 BIOS? ...Mark