Let us continue with the most important part of the test report, the highest possible stable performance. The multiplier adjustment remains on 13x 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 7 RC Ultimate Edition is used as the operating system. The stability was examined with the software Memtest86
and SiSoft Sandra Lite 2010c is for all benchmarks used, because it offers extensive adjustments and a fast result comparison. BTW. the latest SiSoft Sandra version is available on our download server and can be downloaded very fast. All memory benchmark tests are also included in the free Sandra Lite version.
First the maximum possible frequency of the memory module was determined with default 1.50 Volt (1.53V). The memory frequency was increased in small steps with a fixed memory timing of 8-8-8-24 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 8-8-8-24 2T (CAS-TRCD-TRP-TRAS) timings and 1.53V was 733 / 1466 MHz.
Here is a Snipping screenshot of CPU-Z 1.53 with 733 / 1466 MHz and 8-8-8-24 2T with 1,53 Volt:
Of course it’s possible to run much higher frequencies with increased voltages or lower timings, because the frequency values and timings depends directly from each other.
The benchmark comparison of all DDR3 memory modules were tested with the default 1.53 V, where these modules reached 1466 MHz. This highest possible clocking on the default DDR3 voltage was compared with two other settings. On the one hand they were tested with 200 MHz reference clock x6,66 = 1333 MHz and SPD values (SPD values are programmed in the SPD IC by the manufacturer). On the other hand the highest possible frequency was determined at 8-8-8-24 2T with the permitted manufacturer voltage.
With a frequency of approx. 667 MHz the SPD EEPROM autodetection timings were 9-12-12-30 2T (CAS-TRCD-TRP-TRAS).
Here is a Snipping screenshot of CPU-Z 1.53 with 666.7 / 1333 MHz and 9-12-12-30 2T:
Officially Crucial specify the voltage of 1.65 Volt without loosing the warranty. This voltage was also necessary, in order to be able to clock the modules stable with 800/1600 MHz and 8-8-8-24 2T. With 1.65 Volt Vmem and CL8 it was possible to reach a maximum frequency of 1653 MHz on the AMD platform. An inoffical overclocking test outside the manufacturer specification with 2.00 V Vmem offered a maximum of 1680 MHz and offers only a little increasement compared to the permitted 1.65 Volt.
The highest possible frequency with 8-8-8-24 2T (CAS-TRCD-TRP-TRAS) timings and 1.65V was 826 / 1653 MHz.
Here is a Snipping screenshot of CPU-Z 1.53 with 826 / 1653 MHz and 8-8-8-24 2T with 1,65 Volt (manufacturer voltage):
Here are the SiSoftware Sandra 2010c benchmark results:
|Frequency||Timing||Speicher Spannung||RAM Range Int Buff’d iSSE2||Memory Bus Range||Memory Latency|
|220 MHz * 6,66 = 1466 MHz||fix (8-8-8-24 2T)||1.53 Volt||13.52 GB/s||23.00 GB/s||78 ns|
|248 MHz * 6,66 = 1653 MHz||fix (8-8-8-24 2T)||1.65 Volt||15.00 GB/s||25.84 GB/s||69 ns|
|200 MHz * 6,66 = 1333 MHz||SPD (9-12-12-30 2T)||1.53 Volt||12.00 GB/s||20.84 GB/s||93 ns|
By the way, the “Memory Bus Range” is no benchmark value, but this value is quite simple to calculate by the frequency and this is useful for a benchmark comparison.
Here’s a diagram of the benchmark values:
Here is a direct comparison of some DDR3, DDR2 and DDR memory benchmark results:
The Crucial Ballistix PC3-12800 memory modules are with three other kits currently at the top of all benchmark results at standard JEDEC voltage. At the maximal permitted voltage of 1.65 V, which is also programmed in the XMP-1600 profile by the manufacturer, the result was much higher. At this Vmem the Crucial Ballistix PC3-12800 kit reached in RAM Range Int Buff’d iSSE2 of SiSoftware Sandra 2010c a performance of 15.00 GB/s at 1653 MHz, which is a very impressive result.