I will soon be upgrading the Athlon 64 3400+ Venice in this build to an Athlon 64 3500+ Venice to use all the available bandwidth in my motherboard (800MHz HT vs 1000MHz HT).

In order to do that though, I need to make sure my RAM is at the correct speeds as well. I have 2GB total of Super Talent X32PB1GC PC3200 DDR400 memory (4x 512MB), however my motherboard seems to be dead-set on running it at DDR333 speeds. I have tried changing the DDR Clock / Timing Mode value in the BIOS from 2 / 1.66 to 2 / 2 to get it to DDR400 speeds, however, upon supposedly saving the BIOS settings, it always reverts back to 2 / 1.66 upon reboot, forcing me to use DDR333 speeds. I decided to try and change all the memory settings available to manual while changing the DDR Clock / Timing mode to 2 / 2 to see if I could get it to stick at 400MHz, using standard timings for DDR400 as I can't find any information on the correct timings for those particular modules anywhere. Still no dice, the system just acts as if I chose timings that were way too fast and crashes upon reboot, then when I turn it off completely and back on again, all settings are reverted, and it runs at DDR333 again.

The fact that it is simply acting as if I'm not even changing the DDR Clock / Timing Mode setting confuses me greatly. Setting the timings manually and causing a crash upon reboot does not confuse me as much, because at that point I'm setting things manually and things can go wrong very easily there. I just don't see why the motherboard isn't reading the SPD and automatically determining the timings and settings to run at a memory speed that both the motherboard and RAM supports. Any help is greatly appreciated as always.

[EDIT]
It is now working. I have no idea what caused it to work. I just went back into BIOS one last time and changed the DDR Clock / Timing Mode value from 2 / 1.66 to 2 / 2 without changing anything else like I did the first six times I tried this and it just worked. Saved and applied the 400MHz speed perfectly. I made sure I was actually saving the BIOS settings each time as well and I did this change the same exact way as I did it the last six times I tried it. I have no idea why this happened in the first place.