DFI NF4 SLI-DR Expert – Can the best get better?

DFI NF4 SLI-DR Expert: Memory Overclocking and Performance Evaluation

Memory and HTT overclocking has been the forte of the previous generation SLI-DR board. The objective of these tests was to determine the clockability of different DDR modules on this improved version. It has been stated that this board is much more module-friendly with a wider variety of RAM types than the original DFI nF4. We tested modules at their specified rating and then increased frequency to the maximum that we could reach. For this test, we used the A64 4000+ CPU using a reduced multipier of 8x to assure CPU stability.It's to be noted that the use of a higher multiplier would indeed increase overall system bandwidth, but for this test we were looking for the highest memory Mhz and the accompanying bandwidth chart is purely for module comparisons at their maximum fequency. Everest version 2.20 was used to evaluate Read, write and latency.

It should be noted that during the course of testing the RAM and pushing the envelope, the shipping BIOS started to become a bit troublesome, certainly pushing RAM to its limits can wreak havoc on operating systems and BIOS' in the form of data corruption. After corrupting the original BIOS, we could not find another 11/2/05 shipping BIOS. As a result, we could only locate an 11/9/05 BIOS that is optimized a bit more than the shipping BIOS. The original BIOS failure was a blessing in disguise as the board and RAM responded in a very positive manner to the new BIOS. All settings in the BIOS were left as programmed except for the CAS Latency, RAS to CAS, RAS Precharge and tRAS, which were set to the highest stable, benchable settings. Due to the time constraints involved in producing this review, little time was afforded to experiment with further optimum settings. Another week of evenings may have allowed the following modules to scale a tad higher.

NOTE 11/23/05: There is now a shipping BIOS listed at DFI's site for the Expert, along with a newer beta bios.

Modules	Maximum clock	Read mb/s	Write mb/s	Latency
2x256MB Corsair CMX256A-3200LL BH-5	266Mhz @ 3.6v 2-2-2-5 1T	7255	2108	35.9ns
2x512MB Corsair CMX512-3200XL TCCD	310Mhz@ 3.1V 3-4-4-8 1T	7011	3042	38.5ns
2x1GB Corsair CMX1024 4000PT	300Mhz @ 3.1V 3-4-4-8 1T	6703	2686	40.4ns
2x512MB OCZ PC4800EL Elite Platinum Ed. TCCD	300Mhz @ 2.96V 2.5-3-3-8 1T	6991	2950	39.6ns

The new player in the RAM battles was Corsair 3200XL TCCD based modules. Though rated at PC3200, they eventually surpassed the 4000PT and OCZ's PC4800EL coming in at 310Mhz. The BH-5 based Corsair 3200LL, even at 2 years old, did very well - achieving 266Mhz at the tightest timings at 3.6V. An observation to be made, though, is the poor write performance of the BH-5 compared to its TCCD brothers. I also tested 2x256MB BH-5 modules from OCZ and Kingston with much less success, but even at similar speeds, all the BH-5 suffered from this same write fall off in comparison. This may very well be a side effect of a TCCD optimized BIOS, but only with more time to experiment with settings may we have been able to improve the score. That shortfall notwithstanding, the BH-5 clearly can still be called "king of the hill" in the read and latency portion of our evaluation.

All memory module testing was performed with the 4000+. At a future point, we plan to test with the 3500+ Winchester. That CPU had hit a max of 370 MHz 1-1 with 2x256MB modules of G.Skill PC4400LE on the original SLI-D, and results should be very interesting on the updated Expert board.