With DDR400 Into The Future? DDR Memory Based On PC3200 Standard
More clock speed = more performance. This is a statement that is uncontested in most cases. However, in the case of DDR RAM, this statement should be carefully investigated, because ultimately, memory performance does not depend on clock speed alone. The memory timings in particular have a clearly noticeable influence on the overall performance. Making the step from DDR266 to DDR333 means a clock increase of 25%. Even in unfavorable conditions (DDR266 with CL2 vs. DDR333 with CL2.5), the faster memory still brings performance advantages.
However, there's only a 20% difference between DDR333 and DDR400. Therefore, it's possible that a great deal of the performance boost will disappear, simply because there are not yet any memory modules available for DDR400 with CL2. Timings aside, though, the time for DDR400 will come - at the latest, when DDR400 modules with CL2 timing become available.
DDR400 - A Premature Birth?
Having established the fact that a faster memory interface probably cannot be used to full advantage in practice, there's another question of how it performs with the higher memory clock. In fact, there is a fundamental limitation when using DDR SDRAM based on the PC3200 standard: only a single DIM module with 400 MHz can be used! If two modules are used, then the memory clock is automatically reduced to 333 MHz. If three DIMMs are used, then the chipset sets it back even further to 266 MHz!
This can certainly be assigned to the high clock speed, but the suspicions grow that DDR400 is only really useful for the marketing department of the large providers - at least in the near future.
