AMD's AM2: Athlon 64 FX-62 & X2 5000+

Rounding Things Up:

AMD's move to Socket AM2 and DDR2 has been reasonably successful. Comparing Socket 939 performance to the performance of a chip with the same characteristics as it on the new AM2 socket, it can be said that there are some performance improvements, but there are also performance deficits in some situations too. We think that it is safe to say that the move to DDR2 brings incremental performance benefits to the K8 architecture.

Probably the most exciting prospect to come from the introduction of Socket AM2 is the upgrading opportunities that are unlocked. It is now possible to upgrade from a low-end chip right the way up to one of AMD’s dual core chips without having to change motherboards.

The way that AMD's memory clocks are derived could result in some headaches, as the some chips will not run to their maximum potential due to the slightly lower bandwidth available. The bandwidth difference between chips can approach 10%, so we would recommend using an even-numbered multiplier in order to attain the maximum performance potential from the range of processors. Another important thing to consider now is the cache size, as it appears to make a difference now that there is more bandwidth, albeit with higher latencies available to the CPU.

Another interesting comparison to make is the relative performance to the Yonah architecture. Clock for clock, there are many situations where Core Duo is faster than the new AM2 processors, but there are also situations where Core Duo's poor FPU performance is exposed. We think that Intel is aware of the problems with the Yonah architecture and we are expecting them to be fixed when its upcoming Conroe-based Core 2 Duo chips arrive later this summer.

With such a huge architectural change coming from Intel this year, it would probably be wise to wait and see what is just around the corner. There are rarely times when we advise people to wait, but this is probably a good time to sit tight for a few months.

Value:

A quick look at Scan highlights some interesting prices. On Socket 939, the X2 3800+ goes for £191 inc VAT and the X2 4800+ for £409. On AM2, those processors cost £212 and £452 - so you're paying a premium for the new socket and the DDR2 controller.

The new chips released are not cheap, either. The top-end 939 chip, the FX-60, now costs £586. The premium to go up an extra few megahertz to the FX-62 is quite massive, with that chip costing £720. The 5000+ is a slightly more reasonable £486, which isn't much of a jump over the 4800+, as you might reasonably expect.

Memory prices are forever fluctuating, but given that both chip companies are now focused on DDR2, expect the DDR2 prices to fall to below-DDR levels, as demand ramps up. Initial motherboard prices suggest that you'll pay a small premium for the latest technology, but the rollout of a top-to-bottom range of boards from NVIDIA and ATI means there should be something to suit every wallet.

Final Thoughts...

AM2 is going to roll out across AMD's entire range very quickly and if you are in the market for an AMD-based system, it makes little sense to spend money on older technology, unless you've already got a Socket 939 system. If you're looking to build a system, it is probably wise to wait until the summer, as it is likely to be a very interesting second half of the year.