Overclocking help, please!

[ToeJamathon]

Hi, this is my first overclocking attempt and I'm a bit confused so far :/

I have increased the FSB in bios from 200 to 235 and found it to be stable. My issue is that bios is regulating the voltage automatically, because it's set on auto, which makes the cpu voltage hover around 1.5v-1.54v when idle, which I feel is a bit too high (is it?) - ideally I'd like it to stay at the stock 1.4v. I would change the voltage from auto if I knew how, but I can't seem to figure out the options for it in bios. I have a picture to go along with this:

I've left the cursor on the 'CPU Over Voltage', which I assume is the CPU core's voltage bit? Anyway, there is no clear option for selecting 1.4v/1.5v etc.. When I press '+' to increase it to its first increment it goes to 1.1000 (I forget how many zeros it has), so I thought I'd type in 1.4 to this box, which then came up as 1.4000 and was also in yellow text - suggesting an unsafe number?! So I didn't press enter on that one in case I destroyed my cpu! Can anyone help me out here please!

Also, I have an Athlon II X4 640 and Asus M4A78LT-M LE mobo (bios version 0704).

 

[cjgardens]

Either type the number in or press enter and select the volts you want

 

[bifday2k]

as above either type the volts in there like "1.40", or alternatively use the +/- keys on your number pad to cycle through to the desired figure.

 

[ToeJamathon]

Okay thanks. I did have 1.40v in that bracket for a moment, but because it came up in yellow I thought it was wrong or something?

Also, can I safely run this cpu any higher than that? Because it was running at well over 1.5v for about an hour, admittedly it was mostly just idling though, when the motherboard upped it automatically to match the 235 FSB increase.