Intel Celeron

As mentioned above, a Celeron 266 will run at virtually every speed its Cache-Equipped brother, the Pentium II - 266, will using a 4.0x multiplier.  Running at 300MHz (4.0 x 75MHz) and 333MHz (4.0 x 83MHz) isn't much of a problem, although you may want to buy a Fan for the CPU if you plan on overclocking it, as the retail Heatsink tends to get extremely hot after extended periods of use.

If you plan on overclocking your Celeron, you must take the initiative to check with the motherboard you plan on using with your processor to see if it supports the 75/83MHz bus speeds, otherwise you're pretty much out of luck.

Due to the lack of any L2 cache subsystem, the Celeron benefits greatly from increased bus speeds.  With Socket-7 systems, we have proven that an increase in bus speed increases performance considerably as a result of the faster access to the L2 cache.  In the case of Celeron, where there is no L2 cache to access at any speed, the System RAM picks up the slack, and the faster you can access the System RAM, the more your system benefits overall.  If it were possible, a Celeron running at 75 x 4.0 (300MHz), in comparison to a Celeron running at 66 x 4.5 (300MHz) would produce a performance difference much greater than if you compared a Pentium II 300/75 to a Pentium II 300/66 for that very reason.