Intel processors such as the Pentium II, Pentium III and Celeron are based on a Pin Grid Array (PGA) package with a 0.25 micron process and Flip Chip Pin Grid Array (FCPGA) package processors such as the Celeron II and Pentium III "Coppermine" are based on a 0.18 micron process, which are amongst the easiest processors to overclock on today's market. Mainly, because of versatility of their FSB (Front Side Bus) and core voltage settings which are so simple to change one way or another - either it be via hardware or software. Intel attempted to stop us from overclocking their chips by locking the multiplier setting on recent processors, which stopped us from adjusting the processor speed via changing the multiplier. For those of you who are new to overclocking and have no idea what the processor multiplier is, basically it is what sets the core speed of the processor, say for example you have a Pentium III 450MHz based on a 100MHz FSB the multiplier would have to be 4.5. All it is, is simple mathematics - 4.5x100 = 450MHz. However, Intel's attempt to stop us from overclocking their chips, was not 100% fool proof, we still have the FSB which can be changed anywhere from 66MHz to 200MHz to allow for overclocking.
It would have been ideal for Intel NOT to implement multiplier looks so we don't have to put pressure on the rest of the system eg. AGP bus and RAM. If Intel weren't to implement multiplier locks on their processors, we would have had the option of changing either the multiplier or FSB to archive a successful overclock, this would have been extremely handy for those of us that only have PC100 RAM and didn't want to upgrade their memory to support higher bus speeds. Let me explain why, when you overclock the FSB, you are also, indirectly, overclocking your RAM. So, say for example you have PC100 memory and want to adjust the FSB from 100MHz to 112MHz you are in fact overclocking the PC100 memory to 112MHz. Memory companies such as Mushkin, Micron and Kingmax have produced PC133 and PC150 memory modules to allow for FSB overclocking. Without this type of memory technology, many Intel processor users would not be able to overclock their processors as easy as we can today. This is exactly why memory has became a very integral part of any Intel user's system who intends to overclock their processor. A few years ago, one would have not cared what type of memory they were buying for their system. Now however, it is very important to buy branded, fast memory which has been pre-tested to run a certain speeds. When you change the FSB you are also changing the AGP, PCI and ISA buses, the "Clock Divider" is how your peripherals (AGP, PCI, ISA) can operate at lower speeds than your CPU. A clock divider of 2/3 breaks down like this - FSB times 2 divided by 3 equals the frequency of the AGP bus. 100MHz x2=200MHz. 200MHz /3=67MHz... Capiche? don't worry to much, we'll discuss this further into the guide.