1.65 is a little much I'd imagine. Even with good cooling, I start to wonder about any possible effects of electromigration.

That said, intel's specsheets say:

Intel 965 Express Chipset Family - Datasheet
http://www.intel.com/design/chipsets...hts/313053.htm


11.1 Absolute Minimum and Maximum Ratings

Table 10-1. Absolute Minimum and Maximum Ratings
VCC (1.5 V Core voltage with respect to VSS) –0.3V / 1.375V (Min/Max)
VTT (System Bus Input Voltage with respect to VSS) –0.3V / 1.32V (Min/Max)

11.3.1 I/O Buffer Supply Voltage

Table 11.4 I/O Buffer Supply Voltage
VCC (MCH Core Supply Voltage) 1.188V / 1.25V / 1.313V (Min/Typ/Max)
VTT (System Bus Input Supply Voltage) 1.14V / 1.20V / 1.26V (Min/Typ/Max)


which really is extremely low if you ask me, and most everyone runs higher, so I don't know if that's too conservative or what.

Personally, I wouldn't exceed 1.55v. I figure that should be more or less "ok" since gigabyte ds3 automatically does +0.3v when you overclock fsb to a certain point and keep vmch on auto.


That said, it might also not be a bad idea to use a DMM and measure your vmch. When I set 1.55v on my p5b, I actually got 1.60v.