Asus P5B Vcore weirdness

[Allanon]

Hello,

I'm overclocking my C2D E6300 from 1.8ghz to 2.4ghz for quite a while now. Always left it all on AUTO but now I've decided to lower the Vcore to maintain lower temperatures. So, on AUTO it runs on 1.36V and I've changed it to 1.3V in the bios. The weird thing is that both the BIOS,CPU-Z and Speedfan show it's actually 1.216V! Even on stock 1.8ghz it never went that low (1.272V actually). Now, I've been running Prime95 for a while now and no errors. What's going on? I've checked and the frequency is stable at 2.4Ghz as intended...I'm at loss.

 

[RJR]

1.36v Bios - vdroop = 1.272v difference .088v
1.30v Bios - vdroop = 1.216v difference .084v

Don't see what the problem is, you may want to google "vdroop"

 

[Allanon]

Thanks for your answer.

I did google Vdroop but couldn't find it's relevancy in this case. Maybe I've not explained myself well.
When on stock 1.8ghz I see 1.272V in Bios and Cpu-Z,speedfan.
When overclocked to 2.4Ghz I actually see 1.36 in Bios and the programs, not 1.272V. No Vdroop there.
Only when I try to adjust the Vcore myself to 1.3V from 1.36V for example, it drops to 1.216V.

 

[RJR]

OK, 1.30v Bios to 1.216v in CPUZ (or whatever program) is vdroop. It is speced by Intel and adhered to by most MB manufacturers. This spec can be altered by the Bios with LLC (load line calibration) to minimize or completely eliminate vdroop with the risk of higher transient voltage spikes. Depending on the voltage used, length and duration of said spikes you could damage your cpu, hence the spec for vdroop by Intel. Vdroop is completely normal and unless your Bios is designed to not follow Intel's spec (a couple do) you will have it, UNLESS the Bios uses something like LLC to counter this. Your setting on AUTO may have enabled LLC, so that may be why you see a difference with your VDROOP when set to manual.