X-bit labs

DDR2 vs. DDR: Revenge Gained (page 4)

Category: Memory

by Ilya Gavrichenkov

[ 12/17/2004 | 01:46 PM ]

ASUS + Corsair: i865PE Supports DDR533 SDRAM

Talking about the success DDR2 SDRAM has been making in terms of speed and latency, we shouldn’t forget about DDR-based products the memory and mainboard makers continue to improve upon. Of course, the evolution in this area is less turbulent as in the DDR2 field, just because JEDEC’s DDR SDRAM-related standards have long become rock-solid. The development of DDR400 SDRAM ended at the achievement of 2-2-2 timings, so systems with i865 and i875 chipsets seem to have reached their height and seem to have no further reserves for improvement.

But that’s not exactly so. Having successfully mastered the production of DDR400 SDRAM modules with 2-2-2 timings, the manufacturers switched to developing modules capable of working at frequencies higher than 400MHz. For example, even DDR600 SDRAM memory is available in the market now, i.e. it can be clocked at 600MHz. Such memory modules can only be of any interest to overclockers since none of the chipsets supports memory frequencies above 400MHz in its regular operational mode.

Fortunately, mainboard makers addressed this problem. Using undocumented capabilities of the i865PE chipset the engineers made this chipset support 533MHz memory in the regular mode, i.e. at 200MHz FSB. The ASUS P4P800-E Deluxe is among such Socket 478 mainboards. By the way, the ASUS P5P800, an LGA775 mainboard based on the i865PE chipset, features the same capability. Thus, systems with the i865PE chipset have become compatible with faster DDR533 SDRAM memory in the regular operational mode of the CPU.

Still, the use of DDR533 SDRAM hasn’t been of much profit until recently as we saw in our article called Fastest Pentium 4 Platform: Performance of i925, i915, i875 and i865 with DDR2-533, DDR2-400, DDR533 and DDR400 SDRAM. By the results of our midsummer tests, an i865PE-based system with DDR533 SDRAM was no faster than an analogous system equipped with DDR400 SDRAM with 2-2-2 timings.

Things have changed since then. Back in summer we had to use DDR533 SDRAM modules with 3-4-4 timings as faster modules were nonexistent. But now the manufacturers of overclocker-friendly memory have mastered the production of DDR memory capable of working at 533MHz with 2.5-3-3 timings. Such memory modules are evidently going to bring the performance of i865PE-based platforms onto a whole new level.

We have a chance to check this out thanks to Corsair, one of the leading manufacturers of overclocker-friendly memory, who offered us their TWINX1024-4400C25 modules.

These sticks are rated for 550MHz frequency, 2.5-4-4 timings and 2.75v voltage, but they are also perfectly stable at 533MHz frequency with more aggressive 2.5-3-3 timings.

Thus, using a P4P800-E Deluxe mainboard from ASUS and TWINX1024-4400C25 memory modules from Corsair we assembled an i865PE platform that was working at 200MHz FSB, but with high-speed DDR533 memory (2.5-3-3 timings).