BEGINNER help me overclock my q6600 !

Should I also change the RAM freq/vcores ?

I have the same chip, and to get 3.6ghz, I need 1.47500 volts on vcore to be stable with Intel Burn test. To reach 3.0, you simply have to change FSB from 266 to 333mhz, that's all.

4.0 ghz is very difficult to do and requires you get close to the bad side of voltage needed for that CPU at that speed, but is a bit easier on Intel chipsets vs nVidia chipsets.

I'll tell you right now; you will not reach 4.0 GHz with any kind of stability with a Q6600. Upper limit is around 3.6 GHz. OTOH, a Q6600 will run at 3.0 GHz with the stock cooler or 3.3 GHz with even a mediocre cooler.

And when you overclock, you should test your temperatures with something like Prime95 that runs all 4 cores at 100%.

Core2 Overclocking Guide (generic guide based on an Asus motherboard)
http://www.tomshardware.co.uk/forum/259899-11-core-over...

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- or whatever 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 266 MHz, your memory clock should be at 533 MHz.

Download CPU-Z to check your FSB:RAM ratio. It should be a 1:1 ratio.

Don't bother trying to overclock your RAM.

Do not increase your core voltage past 1.50 volts and keep your load temps under 70 C.