What exactly are you doing? You're going to buy a new computer and are going to buy the motherboard first? And your old computer has a CPU that is incompatible with the new motherboard? If that's the case, what's the rush in updating the bios? Just wait until you get the new, compatible CPU, then update the bios. The bios update is really a simple process and isn't that big of a deal if you're just building the machine.