Why would you want to use 133MHz (266DDR) and give up the ability to overclock your PCI, AGP, IDE, and memory??? Both CPU's handle 133MHZ+ FSB, but why use it? Everything runs faster here using 112MHz FSB, as all Buses are overclocked, and memory has the option of overclocking as well, to 149MHz, (HClK + PCICLK), but 133MHz does not have that option. Also can get higher end results MHz using 112 Vs. 133, as more usable multiplier options are available. Even bumping FSB up to 140MHz (280DDR), yielded net results that were poorer than 112MHz fsb, as buses and memory are overclocked less, along with the limited usable multipliers.