Performance in Memory Subsystem Tests
We first ran synthetic memory tests.
SiSoftware Sandra 2005 doesn’t think much about DDR700 SDRAM: the increase of the Command Rate parameter to 2T leads to higher memory latency as well as to lower bandwidth. So, the first diagrams of our tests already show that you shouldn’t expect much from DDR700 SDRAM.
ScienceMark 2.0 agrees with Sandra 2005 respecting the bandwidth reduction. As for the memory latency, there is a certain pattern here:
As you can see, the latency of DDR700 doesn’t suffer much from the Command Rate set at 2T. Thanks to the extremely high frequency, this memory subsystem has a normal latency, comparable to that of DDR400 SDRAM subsystems.
Since the effective system performance comes from both bandwidth and latency, we also ran PCMark05 to get an overall performance rating of each tested memory subsystem:
According to this test, the memory performance scales up along with the frequency, notwithstanding the worsening timings. This rule, however, doesn’t apply to DDR700 SDRAM. The performance of this memory type is close to the results of the 560MHz DDR SDRAM due to the Command Rate parameter being set at 2T.
Yet it’s not very correct to make a final opinion basing on the results of synthetic benchmarks only. Let’s go over to complex tests.