I have an E8400 and an Asus P5Q Pro Turbo, and would like to overclock it. Appreciate any help, Thank You all.
You can read on this section about how to overclock CPU (sticky on the first thread on this section).
Basically, you are playing with multiplier and FSB. Your stock speed is 3.0GHz, right? Maybe you can go up to 3.4GHz or more if you're lucky without raising the VCore.
And remember to watch the temps, do not get it above 65'C.
The specific link is this one:
This is our generic guide. Next stop should be a guide for your particular motherboard. Google is your friend.
Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the System Memory Multiplier (or whatever your BIOS calls it) from AUTO to 2.00, 2.00B, or 2.00D - whichever you need to set the Memory Frequency to twice the FSB. Then when you increase the FSB, the memory clock will rise in in proportion with it. At an FSB of 333 MHz, your memory clock should be at 667 MHz.
Download CPU-Z to check your FSB:RAM ratio. It should be a 1:1 ratio. Core2 systems gain little from overclocking memory.
During Prime95 or a similar program, keep your load temps under 70 C. And do not exceed 1.45 volts on the CPU cores.