4th time in last week I've posted this, Someone want to make an OC 101 sticky?
This sort of info is Motherboard specific, but in most cases the menu's and settings are common. It breaks down like this:
- You CPU has a frequency
- Your Memory has a frequency
- Your PCI bus and all other sundry busses have a frequency
They are all related as (usually) one single clock genrator is used to get the original clock speed. The relationship is often like this, although there are ALWAYS exceptions:
CPU speed = Memory speed(before DDR or QDR) x Multiplier value.
PCI speed = Memory speed(before DDR or QDR) / 3 (or 4 or even 5, the goal speed is 33Mhz as PCI devices often hate high PCI bus speeds, such as hard discs=data coruption!!!)
AGP Speed = PCI speed x data rate(2x, 4x, 8x), so 2x = 66Mhz if the PCI is 33Mhz and so on
Multipliers are locked on P4 and can be changed on Athlons. Some motherboards allow the PCI clock to be locked into 33Mhz, this is good.
So, original speed of memory on a 400Mhz P4 is 100Mhz(400Mhz QDR) and the multiplier is 20, giving 2Ghz. To overclock, set the fsb to 110 and the CPU speed upon next boot will be 2.2Ghz (110x20).
Et Viola, your first overclock. Now I have simplified the process by a great margin and to answer your question about BIOS menu's, this will be clear if you get an Overclocking friendly Motherboard( ASUS, Abit, Epox), by way of the manual. They usually have a menu with the main overclocking features in one place.
Hope that helps!