Quote Originally Posted by Century Phoenix View Post
Ok.
But I don't understand one thing:
I disable the EIST in my Bios (multiplier: 8, FSB 410MHz), I keep enable the C1E.
When my cpu is idle, the multiplier is 6 and the VCore 1.248Volt, when the system is busy (with Boinc), the multiplier is 8 and the Vcore 1.216Volt ...

Normal?
Yep, I should have precise it like cumulonimbus said. In your case, on load vcore is lower, is called vdroop.
When you OC, C1E is useless as you see, the vcore won't decrease, and C1E acts as EIST alone