Stability Testing

To determine whether a certain speed/timing is stable I did 3 passes of a standard memory test in Memtest86. Here are the timings and theoretical memory bandwidth results.

Timings @200 Mhz, for all modules - Dram/FSB: 1:1 CPC: Enabled



All other timings are set manual and kept the same, except for Drive strength, Data drive strength and Clock Timing Skew. DQS : Auto - Ds: Level 6 - DDS : Level 4 - CTS : Delay 300ps - MAL 7.0ns - RPT : 5,5ns - ICL 256 Cycles - DC: Disables - R/W Queue Bypass : 16X - Bypass max : 7X - Burst length: 4 Bursts

If you`re looking at the maximal theoretical bandwidth, the 2x 1Gb modules do have an advantage regardless of the slightly less tight timings. How much remains of this advantage in real life performance is something I?ll test later on.

Now we raise the FSB to 233 Mhz for the Infineon CE5 and the Corsair CH5, as these both can hold their timings at 2-3-2-8.

Timings @233 Mhz, for all modules - Dram/FSB: 1:1 CPC: Enabled



All other timings: DQS : Auto - Ds: Level 6 - DDS : Level 4 - CTS : Delay 450ps - MAL 7.0ns - RPT : 5,5ns - ICL 256 Cycles - DC: Disables - R/W Queue Bypass : 16X - Bypass max : 7X - Burst length: 4 Bursts

Again we see a nice advantage for the 2x 1Gb modules.

Now we take the jump to the FSB at 250Mhz. All modules, except the Team BH5 2,5-4-4-8 ( Max-out @223) are able to run these speeds, with adjusted timings.

Timings @250 Mhz, for all modules - Dram/FSB: 1:1 CPC: Enabled



All other timings: DQS : Auto - Ds: Level 6 - DDS : Level 4 - CTS : Delay 450ps - MAL 7.0ns - RPT : 5,5ns - ICL 256 Cycles - DC: Disables - R/W Queue Bypass : 16X - Bypass max : 7X - Burst length: 4 Bursts

Again we see an advantage for the 2x 1Gb modules, but the CH5 based Corsair with its stricter timings is starting to pick up pace.

Timings @275 Mhz, for all modules - Dram/FSB: 1:1 CPC: Enabled



All other timings: DQS : Auto - Ds: Level 6 - DDS : Level 4 - CTS : Delay 600ps - MAL 7.0ns - RPT : 5,5ns - ICL 256 Cycles - DC: Disables - R/W Queue Bypass : 16X - Bypass max : 7X - Burst length: 4 Bursts

Despite the better timings on the OCZ TCCD 2x512Mb kit, its memory bandwidth does not surpass the A-DATA. Team Group?s CE5 is still in the lead.

Highest Stable Speed

As with all overclocking, once you pass the manufacturers specifications you?re in a free for all zone, anything goes and nothing is sure. What performance I?ve extracted from these modules depends on many variables, including motherboard, CPU, bios and simple sample variance. While these overclocking results can give you an idea of what can be obtained, it?s not a certainty that you will get the same results. Please keep this in mind when looking at these figures.

A-DATA UCCC maxed out at 278Mhz using 2.75v at 3-4-4-8.

Team Group CE5 267Mhz 2,5-3-2-8 @2,95V || 287Mhz 3-3-2-8 @ 3,05V || 292Mhz 3-3-3-8 @ 3,1V