I'm completely new to overclocking and I now overclocked my E8400 CPU to 3.2 Ghz by setting PCI-E frequency to 100, disabling C1E and EIST (for testing), increasing the host frequency to 350 mhz and setting the FSB:RAM ratio to 1:1. The only thing that's bugging me is the voltage.
I first set the voltage on Auto in the BIOS and it set a value of 1.28v, which seems to be way too high for such an overclock. Then I checked the "VID" value in CoreTemp, which I understand to be the "normal" voltage for my own CPU, and it showed 1.225v. So I set the "CPU Voltage" to that value in the BIOS, but now CPU-Z is showing the vcore to be 1.18v.
So three questions:
1- Can I generally set the voltage to something lower than the VID value, or is that the absolute minimum?
2- Is it normal that CPU-Z is showing a lower vcore value than what I set it to?
3- Considering that I set the voltage to 1.225v, can I also go up to 3.6 Ghz on that level, temps etc permitting?
Alright, thanks. So it's okay if in CPU-Z I see a lower value than the VID. And would I need to boost the voltage to go up to 3.6 Ghz later?
I can't say because it differs by every cpu. You have to use stress testing programs such as Prime95 to see if your cpu is stable with the voltage at 3.6ghz. Increase frequency by 0.1 until your unstable(making sure your stress testing every time) and when you're unstable increase voltage by a notch until you're stable. Continue doing this until temps or voltage is too high or you're at the frequency you want.
Alright, thanks. So it's okay if in CPU-Z I see a lower value than the VID.
Yes. Your voltage increase won't show up in CPU-Z, only in your BIOS.
Reinforcing what bear95 said, you want the lowest possible voltage for a given clock speed without the system crashing. If you can run prime95 stable for a while (I'm happy with around 30 minutes, some people like to leave it overnight). Higher voltage mean more heat, and heat is the enemy.