CPU Voltage- DS3

I have an E6400 running @ 3.2G

I don't understand at all..I disabled all the auto voltage controls in the BIOS (DS3).
The CPU voltage given by both CPU-Z and speedfan are 1.264 -1.280 V. The default is 1.325 V. Why does still it lower my voltage?

I don't think it is my power supply, since the CPU voltage is quite steady in the range of 1.264 -1.280 V.

Do they have different names in the DS3 bios? I don't see them.

I disabled EIST, set the system voltage to "Manual", and set the CPU

voltage at 1.325. Nothing happened.

I don't know which has the inferior voltage regulators..but DS3 is a little more expensive than the S3.

I already tried two different versions of BIOS. Same.

Hmm..is my MB faulty?

Ultra 500W; I know it is not top-of-the-line, but it seems that all the voltage outputs, including the CPU voltage, have been steady.

I hope it is the former; the latter would limit the board's overclocking potential or the choice of CPUs if I want to upgrade.

S3 and DS3 are same, but the DS3 has solid capatitors.
D stands for "durability enhanced"

@cybernike
I have the same maiboard, same CPU, OC-ed at same clock!

I have EIST & TM2 enabled in BIOS. The CPUz is showing different voltages. For example, CPUz shows 1.213v, but in BIOS it is 1.4675v

Not quite. The X6800 stock voltage is 1.38V. +10% is not too much.
I have less FSB variations, between 399.8MHz and 400.2MHz :