i& overclocking - What cpu Voltage to use ?

[wombraider]

Hi,
I am mucking about with OCing my i7 920 I have left the cpu voltage in auto
In cpu-z this reads back as 1.375 and the idle temps are a little high 45-47 deg c

Can anyone tell me what the recommend voltage on the cpu should be?

I am using a noctua cooler ( think I might put a better fan on it )

currently clocked at 3.2G with HT off and Boost off

 

[wombraider]

Heatsink was defo correctly applied , might have to check my air intake filters tho and give em a clean

Coretemp does not return any vid value for this chip

Bios says 1.29V , but cpu-z reads 1.375ish

Can anyone else respond who has oced their i7 with what voltage they used ?