yes you should believe cpu-z
ok here are more details about my personal experience with this board regarding voltages. your mileage may vary
its also very unaccurate as i've forgotten details like actual values and numbers
with bios 1001:
when the vcore was set to "auto", it actually ran at around 1.48volts. weird that...
when it was set manually to 1.4 it was exactly 1.4, when set to 1.5 it was 1.5.
i had options up to 1.6something for the vcore. but all options above 1.5 didn't work, if i remember right they were the same as 1.5
with bios 1002.3:
the "auto" vcore properly results in 1.4 volts, the options go up to 1.575 and supposedly all work properly. i've tried only the 1.4, 1.5 and 1.575 settings myself but they were ok.
what clockgen's setting really mean and how they work:
(this is just a wild guessing on my part, based on something i read somewhere)
I
assume that the board's vcore selection works internally on two levels/steps...
At the basic level the voltage can be set to some values that are quite some distance apart from each other, i.e. 1.525v, 1.4v, 1.2something
Then at a second step it applies something like a "fine-tuning" to the selected basic voltage, i.e. +3.5% +1.7% +0% -1.7% -3.5%
So what clockgen actually controls is the "fine-tuning" level only, and its settings mean a certain change of the basic voltage for example 1.40 means +0%, 1.45 means +3.5%.
Settings above 1.45 are the same as 1.45, i.e. +3.5%, that's why clockgen always claims 1.45 is max.
This way you can get to 1.58 if you set 1.52 in the bios (it does it like 1.52 on the firs level and +0% on the second) and then 1.45 in clockgen (which makes the second stage +3.5 % resulting in 1.58v).
This explains also why i.e. if you set 1.5 in the bios, you'd see 1.375 in clockgen. the bios makes 1.5 by setting 1.52 at first stage and -1.7% at fine-tuning, and clockgen only sees the finetuning and it corresponds to its 1.375 option.
I hope this whole thing made sense. But keep in mind its just my understanding, which might be different from reality.
Anyway, the important thing is voltages seemed to work just right with the beta bios, so if you don't want to deal with the original's kinks just flash to the beta. And for checking what voltages you get, don't use clockgen, it's settings mean something completely different from what's written on them
cpu-z should probably be reliable info, i use speedfan myself though.