Originally Posted by Marios
I think this is the first time ever to compare DDR500 DDR400 timings on the same system, at the same CPU and Northbridge speed.
This was possible by implementing the hidden 5/4 divider on Athlon 64 Rev E CPUs.
Comparing DDR500 - DDR400
DDR500 1T, 3-4-4-10-14-18-3-4 Sandra=5775
DDR500 1T, 3-3-3-8-12-16-3-3 Sandra=5775
DDR400 1T, 3-3-3-8-12-16-3-3 Sandra=5514
DDR500 is faster by 260 points.
Comparing 1T - 2T DDR500
DDR500 1T, 3-4-4-10-14-18-3-4 Sandra=5775
DDR500 2T, 3-4-4-10-14-18-3-4 Sandra=5274
1T is faster by 300 points.
Comparing 1T - 2T DDR400
DDR400 1T, 3-3-3-8-12-16-3-3 Sandra=5514
DDR400 2T, 3-3-3-8-12-16-3-3 Sandra=4654
1T is faster by 860 points.
Comparing different timings with the same tCL at DDR400
DDR400 1T, 2-2-2-6-9-14-2-2 Sandra=5614
DDR400 1T, 2-3-3-8-12-16-3-3 Sandra=5574
Difference 40 points. (almost nothing)
Comparing different timings with the same tCL at DDR500
DDR500 1T, 3-3-3-8-12-16-3-3 Sandra=5775
DDR500 1T, 3-4-4-10-14-18-3-4 Sandra=5775
Difference 0 points.
Comparing tCL2 - tCL3
DDR400 1T, 2-3-3-8-12-16-3-3 Sandra=5574
DDR400 1T, 3-3-3-8-12-16-3-3 Sandra=5514
Difference 60 points. (small)
Comparing different timings
DDR400 1T, 2-2-2-6-9-14-2-2 Sandra=5614
DDR400 1T, 3-3-3-8-12-16-3-3 Sandra=5514
Difference 100 points.
Comparing DDR500 1Τ - DDR400 2Τ (BIOS Default)
DDR500 1T, 3-4-4-10-14-18-3-4 Sandra=5775, PCMark05=5759
DDR400 2T, 3-3-3-8-12-16-3-3 Sandra=4654, PCMark05=5621
DDR500 1T is faster by 1121 points.
In this case we have a 25% Sandra boost and a better PCMark05 score by 138 (2,45%).
Conclusions
The most important DDR speed factors in my case were 1T and memory frequency in this order.
Should I dissable 2T at DDR400 or leave it as is and raise the memory frequency at DDR500?
At DDR400 1T I got a 5514 score while by just raising the frequency to DDR500 2T I got 5214 points.
ASUS did a great job with 1009 BIOS.
Auto memory settings gave me the best stable speed as long as I enabled 1T manually.
My Ballistix are DDR500, 3-4-4-10-14-18-3-4.
With default BIOS settings on earlier than 1009 BIOS I would lose a quarter of my DIMM's speed and 2.5% of my PC speed.
This is how I checked.
Athlon 64 4400+ A8N32-SLI Deluxe BIOS 1009.
All tests run at the same BIOS default settings (CPU 201X11=2211MHz).
I used the latest Sandra 2005-10-10-69 version dlded from extremeoverclocking.com
My timings are: tCL-tRCD-tRP-tRAS-tRC-tRFC-tRRD-TWRT
DDR400 was 201MHz
DDR500 was 244.44MHz
(manually calculated, since no program understands a 5/4 divider)
Sandra's 2005 Memory bandwidth Benchmark scores were taken as an average of 5 checks.