Let us begin with the most important part of the test report, because the optics and packing is of course rather secondary and the possible stable performance is the most important factor. CPU on different frequencies depending on the reference clock for the different memory benchmarks. Thus the multiplier adjustment remains on 9x with all frequencies, because an adjustment for the CPU in half multiplier steps would be too inaccurate to get nearly the same CPU frequency for all tests.
Microsoft Windows XP Professional SP2 is used as operating system. The stability was examined with the software Memtest86
and SiSoft Sandra Lite 2007.SP1 program is used for all benchmarks, since it offers extensive adjustments and a fast result comparison.
First the maximum possible frequency of the memory module was determined. The memory frequency was increased in small steps with a fixed memory timing of 4-4-4-10 2T and default memory voltage, as long as the detailed memory test with Memtest86 runs without any errors. This quite long testing time ensured that this frequency works really stable with these modules.
The highest possible frequency with 4-4-4-10 (Tcl Trcd Tras Trp) timings was stable with amazing 461 MHz.
It’s possible to run clearly higher frequencies with increased voltages or lower timings, because the frequency values and timings depends directly from each other. Officially Crucial specify the highest voltage of 2.2 V without loosing the warranty and this is a considerable voltage to get nice overclocking results (the default DDR2 memory voltage is 1.8 Volt).
This highest possible frequency was compared to two other settings. On the one hand 461 MHz with SPD values (these are given by the manufacturer in the SPD IC), and on the other hand 200 MHz (x2) with SPD values.
By the way, the “Memory Bus Range” is no benchmark value, but this value is quite simple to calculate by the frequency and is useful for the benchmark comparison.
Here’re the benchmark results:
|Frequency||Timing||RAM Range Int Buff’d iSSE2||Memory bus range|
|461 MHz||fix (4-4-4-10 2T)||6437 MB/s||14752 MB/s|
|461 MHz||SPD (5-5-5-18 2T)||6385 MB/s||14752 MB/s|
|200 MHz||SPD (4-3-3-9 2T)||4671 MB/s||6432 MB/s|
Here’s a diagram of the benchmark values:
Here is a direct benchmark result comparison of some DDR2 and DDR memory modules:
As to be expected the results of the Crucial PC2-8000 CL5 memory modules are also with the default voltage higher than the results of conventional PC2-5300 CL3 or PC2-6400 CL4 modules. The frequency of 461 MHz was reached with the Athlon 64 3000 CPU on 9x 256 MHz reference clock = 2304 MHz and fast 4-4-4-10 2T timings. So if the motherboard doesn’t offer features to adjust the memory frequency full asynchronously or just in large steps, it is nevertheless possible to get good overclocking results. It was possible to overclock the PC2-8000 modules in the test over 500 MHz with little increased voltage and this is a considerable value with these memory timings. A well selected memory voltage (VDDR/VMEM) is thus very important particularly with these modules to reach high overclocking results.