j3pflynn, kpf, the 'unregistered memory factor' gives a boost two ways. On the same clocked DRAM, it has less latency. The more significant boost is from the fact that unregistered memory generally can be implemented at one speed grade faster than registered. Expect socket 939 to work with faster DRAM (I don't think AMD said anything on this next point, but I would think that would be the vehicle to introduce DDR2).