Performance
Table of test results
| Corsair's TwinXP1024-3200XL (CMXP512-3200XL) | G.Skill's F1-3200DSU2-1GBLE | OCZ Technology's PC3200 EL Platinum Rev2 | |
| Maximum speed @ SPD and 2.75V | 218MHz 2-2-2-5 |
219MHz 2-2-2-5 |
217MHz 2-2-2-6 |
| Maximum speed @ SPD and up to 3.0V | 222MHz 2-2-2-5 |
224MHz 2-2-2-5 |
225MHz 2-2-2-6 |
| Maximum speed @ any timings, 2T and up to 3.0V | 282MHz 3.0-4-4-10 |
302MHz 3.0-4-4-11 |
296MHz 3.0-4-4-10 |
| Maximum speed @ any timings, 1T and up to 3.0V | 274MHz 2.5-4-3-10 |
291MHz 2.5-4-4-8 |
294MHz 2.5-4-4-8 |
Summary
In almost all cases, going over 2.90V bought me nothing during the testing with the modules. The only time I strayed over that line was with 2.95V for the OCZ to reach 294MHz @ 2.5-4-4-8, 1T command rate. With up to 4.0V available from the DFI mainboard (in reality I've found it to be around 3.7V), stretching the mainboard's memory voltage legs bought me nothing, and even further instability in most cases.It takes multiple hours to sit with Memtest86+ and find the limits, and even then they're not indicative of what you might find with another mainboard, or even the same mainboard with a different PSU (since PSU affects clean voltage supply to the Vdimm circuit, and on to the modules themselves). However, if you keep the system constant throughout, the results are valid.
There are two main conclusions to draw from the test data. Firstly, Samsung TCCD-based modules will see you run high memory clock on Socket 939 Athlon 64, with good timings and at low-ish Vdimm. Most mainboards will give you 2.85V Vdimm these days, and that'll buy you ~270MHz @ 2.5-3-3-8 with all the modules.
Secondly, the Corsair seemed to run out of steam at the really high end, as the G.Skill and OCZ fought it out. It seems to be related to a setting in the DFI's BIOS that's outside of the usual CL-Trcd-Trp-Tras quartet of timings you'll see quoted, so if I can get any more information out of DFI or Corsair about the issue I'll update the article. I get the impression the Corsair is capable of the same ballpark speeds as the others, with a tweak of a setting called Tref.
All three module kits will give you ~DDR450 at really tight latencies, with around 2.85V and in the main, the modules prove themselves to be very capable on the test platform at a wide range of test settings and speeds. Voltage is their only nemesis, not responding to anything over 2.95V at all.
Result Graphs
