Memory - Is DDR333/400 worth it?
As I'm sure a lot of you have seen after the release of the VIA KT333 chipset, the AMD Athlon processor does not have any real-world benefit from the extra bandwidth that DDR333 (or PC2700) memory provides and the performance increase over the KT266A chipset is negligible. This is because it's 133MHz (266MHz DDR) is bottlenecking performance. Sure, this would change if AMD released a processor that features a 166MHz bus, however, with no 166MHz bus processor to be seen on AMD's roadmap up to 2003, I feel that we may be waiting for quite a long time.
The Pentium 4, however, is a different story. It features a "quad-pumped" 100MHz (400MHz effective) bus and as we have seen from performance numbers of DDR333 chipsets such as the SiS645DX, the Pentium 4 can make use of this extra bandwidth because its FSB is not a bottleneck on performance.
With a rumored KT400 chipset on the way that gives DDR400 support to the Athlon, I can't help but wonder, "what's the point?". The Athlon can't even take advantage of 166MHz memory so what performance difference will we see when using 200MHz memory? That said, VIA are not the only ones that have released a DDR333 based SocketA chipset. SiS was the first to release a DDR333 chipset for the Athlon, and VIA, feeling the need to be competitive, brought out a DDR333 chipset of their own. VIA will most probably do the same with their DDR400 chipset as SiS are just finishing work on their own DDR400 Pentium 4 chipset, the SiS648. I say, let SiS release their DDR400 Athlon chipset. When consumers see that it does not give any better performance over DDR333 and DDR266 chipsets, they won't buy it.
On the Pentium 4 side of things, again, the situation is very different. Its 400MHz bus can make use of DDR400's extra memory bandwidth and when a DDR400 chipset is released for the Pentium 4, we will see performance numbers like never before. With Intel planning on upgrading their Pentium 4 to a 533MHz bus in the near future, I am quite positive that the Pentium 4's bus will never be a bottleneck on memory performance.
My suggestion to chipset manufacturers is, bring out a DDR400 chipset for the Pentium 4 as this is where it will be most effective. Until AMD decide to move the Athlon to a faster bus, releasing Athlon chipsets to support faster memory is doing little more than wasting time.