As for DDR400 that works synchronously with the system bus, the changes of its memory timings do not cause any significant change of the bandwidth. They mostly affect the latency. Note also that the CAS Latency parameter alone does not influence the memory subsystem speed too much. Two other parameters, namely RAS# to CAS# Delay and RAS# Precharge, affect the results much more heavily. This is a curious fact, considering that many memory sellers usually draw the customer’s attention to the CAS Latency parameter, often without even mentioning the other ones. So, we recommend you to note that modules with CL = 2.5 or 3 will not in all probability work with minimal RAS# to CAS# Delay and RAS# Precharge.
The next benchmark is SiSoft Sandra 2003:
It simply confirms the things we have said above: CAS Latency is not to be considered the main factor in determining the DDR400 memory speed in the Pentium 4 platform. In our tests, we have a clear example: the memory with timings set to 2.5-3-3-6 is faster than the memory with 2-4-4-8 timings.
The same is true for the results we got in the memory subsystem test from PCMark2002. As for the CPU Score, this value largely depends on the processor frequency, as this test doesn’t process any big data amounts that would require intensive memory access. However, I think we’ve had enough of synthetics, let us turn to real applications now.