1st. You need to know how to overclock
How is this possible? Well the processor achieves its clock speed by multiplying its FSB or Front side Bus-Speed or the speed in which information travels in the various "buses" in the system by a particular multiplier
For example 266Mhx is achieved through multiplying 66 (MHz) it's FSB by 4 its multiplier.
66 X 4 =266
As processor makers realized the potential of processors being overclocked and being sold by dubious traders to unsuspecting customers they tried to prevent overclocking by locking the multiplier value. So most Pentium II Celerons and later processor as well as Athlon & Thunderbirds are clock locked. But it is still possible to overclock these processors by increasing the Bus-speed, which most Motherboards, allow you to do.
2nd.2) Overclocking in the BIOS vs. overclocking software - Whenever the option exists, manipulating BIOS settings is the best way to accomplish overclocking. BIOSes on value/low end motherboards and on proprietary systems such as Dells and HPs generally have few to no options available for overclocking. On such systems, there is the potential to overclock through software, though there is not a single piece of software to overclock every board.
3rd. CPU FSB vs. external clock speed - Intel overclocking is achieved via the front side bus or system bus. Depending on your system, it can be noted as FSB, CPU frequency, CPU speed, clock speed, or something similar in the BIOS. Intel CPUs more recent than Pentium 3s are “quad pumped”. This means that the external clock speed (the value shown in the BIOS) is one fourth the FSB, i.e. external clock speed = FSB/4.
4) DDR frequency vs. external clock speed - Conversely, DDR RAM transmits data on both sides of a tactical signal, effectively performing two functions per single clock cycle (i.e. DDR frequency = 2 x external clock speed). That is why it’s referred to as Double Data Rate RAM. The discussion of RAM applies equally to DDR, DDR2, and DDR3. There are a variety of ways this is displayed in the BIOS; some display the DDR frequency and other show it as a ratio of the CPU:RAM, which will be discussed below.
5. http://www.overclock.net/intel-cpus/1567-i...king-guide.html