ASUS M2N4-SLI not running at 400 Mhz FSB?

[se7en16]

Here is my setup:
ASUS M2N4-SLI mobo
AMD Athlon 64 3800+ @ 2.4 Ghz
1 GB Corsair XMS2 DDR2 800 (PC2 6400) RAM
500W Power supply

I noticed that it is running as 200 Mhz FSB with a 12x multiplier (equals 2.4 Ghz). Shouldn't it be able to run at 400 Mhz FSB with a 6x multiplier, since I have DDR2 800 RAM?

After installing the most recent BIOS, I tried editing these settings, but when it restarts, it just shuts off. After doing this twice, it gives me a system bot error and lets me back into the BIOS.

I even tried 250 Mhz with a 9x multiplier, and instead of shutting off, it sounds as if it reboots itself a couple times before giving me the same error.

At first, I thought it was the DDR2 voltage, but the highest it goes is 1.95v.

Am I doing something wrong, here? Please help!

 

[Peter]

Welcome!

First of all, Athlon-64 architecture does not have a Front Side Bus (FSB) at all. The 200 MHz is the system's common reference clock, and that's always 200 MHz.

Even if the system has a CPU front side bus, the RAM speed isn't necessarily anything to do with it. These are separate busses (if the CPU bus still actually exists, which for AMD isn't the case anymore.) Your DDR2-800 RAM runs at (close to) 400 MHz like it's supposed to, right?

Besides, screwing around with the reference clock does little to actual performance. Just leave it as it is, everything is correct.