We’ve hinted at the arrival of AMD’s new AM2-socket a few months ago in an editorial discussing upcoming AMD and Intel processors. AMD’s AM2-socket will bring DDR2 memory support to the Athlon 64 processor, which will feature a DDR2-compatible on-die memory controller. Hence the new socket, as this new memory controller is not compatible with socket-939 which only supports DDR. Early reports of the performance of CPUs sporting this new socket indicate that their performance is quite a bit less than what we’re used to from a similarly configured socket-939. This is surprising since DDR2 provides more bandwidth, so should in theory also be able to offer better performance. However some report a reduction in performance by as much as 50%, that’s no small margin to be honest.
So this begs the question whether AMD will launch the new socket-AM2 on schedule, or whether they’ll postpone the launch to wring more performance from it? But wait, haven’t we seen a similar situation before? Well, actually we have. Remember when Intel introduced their new DDR2 platform based on the 90-nm Prescott core Pentium 4 processors? They too saw a significant reduction in performance which resulted in many people ridiculing Intel for releasing a new platform with sub-par performance. Intel however was quick to comment that they needed DDR2 and the 90-nm Prescott core to scale up to >5GHz clockspeeds. In hindsight they gambled on the wrong horse as Prescott never scaled up that far and DDR2 did nothing to raise the performance bar until DDR2-800 became available. By then Intel had already strayed from the beaten path and had dropped out of the clockspeed race as AMD kept beating them in the performance department with lower clocked processors.
Will AMD suffer the same fate? Well, we doubt it, although they might not be able to reap the benefits of this transition until they finally manage to get their 65-nm processors shipping in volume. Despite the enthusiasm with which they announced their switch to 65-nm in the ‘near future’ we all remember what an ordeal it was for them to get to 90-nm reliably and be able to ship in volume. Nevertheless with the arrival of 65-nm dual-core AMD processors we might see the first glimpse of some of that DDR2’s untapped potential. If you’re shopping for a new AMD based PC now, don’t hold out on your purchase, these changes are still a good two years away, so it is quite safe to buy a socket-939 based PC today.