Asus P5K Deluxe Timings/Subtimings
4:5 Memory Divider

Next up is looking at how 4:5 memory divider behaves on Asus P5K Deluxe using 0304 bios. First feature I noticed was that changing memory dividers also triggers off the the auto shutdown and auto restart process on only the bios exit in which you change the memory dividers. This is normal in order to properly set up the settings and only happens on the first change of memory dividers at exiting bios. Second item I noticed was there might be a bug in that PCI-E Frequency isn't locking properly when set to 100Mhz on first boot up after changing to 4:5 memory divider. Setting PCI-E Frequency to 102Mhz fixed the problem completely though. I've passed this finding onto Asus folks so let's see what they can do for the next bios release.

For 4:5 memory divider testing right now, I just wanted to find out what the bios set's for AUTO for the subtimings as memset doesn't support P35 Bearlake chipset as yet there's no way to know from within windows what AUTO values are used for subtimings.

I decided to run 2 sets of tests, one at AUTO subtimings and one at 3-30-3-3-3 manually set subtimings.

At AUTO Subtimings (largesystemcache enabled from now on):



Manually set subtimings (largesystemcache enabled from now on):



Important to note, when looking at the Super Pi times, is that using E6600 B1 stepping ES cpu the Super Pi times are approximately 10-22 seconds slower clock for clock than retail Core 2 Duo B2 stepping cpus. However, even for B1 stepping cpu it seems the 32M times are off a bit from past B1 times at 4:5 on other boards, I'll have to pluck in a B2 stepping cpu latter to see what's happening.



Again a similar pattern emerges as with 1:1 memory divider test in that manually set 3-30-3-3-3 sub timings is only 0.437% faster than AUTO subtimings configuration. In other words, AUTO subtimings values even on 4:5 divider are set pretty tight to begin with. This maybe good if you have a nice pair of Micron D9xxx based DDR2 memory with adequate vdimm memory voltage but might be too tight for other value memory.

I'm not sure if AUTO subtiming values are set by the memory's SPD programming ? If that was the case, then how fast or slow AUTO subtimings are would be dependent on your specific DDR2 memory modules' SPD programming ??

For value ram 4:5 divider mode, maybe it might be easier to start off with manually set subtiming values to 6-42-10-10-10 since it's alot looser and work your way down to tighter values ?