Only few weeks ago, Intel introduced their Solano chipset (i815), which hasn't quite been able to fulfill our performance expectations derived from the overclocked 'BX133'. Solano's performance is still somewhat behind the two years old 440BX chipset, making the latter still an interesting choice, as it is both very matured and also fast - even though it only comes with AGP 2x and UltraDMA/33.
Originally, the BX was only specified for 66 and 100 MHz front side bus operation, but today most technically knowledgeable end users don't care much about this restriction. You might never be able to buy a whole system based on the BX-chipset running at 133 MHz FSB at any shop, yet performance freaks hold their self-made 'BX133' systems in high regards. If you want BX133, you will have to get it running at this speed by yourself. You will also have to take the minor risk that your machine might not run 100% reliable at the 133 MHz FSB, mostly due to the overclocked AGP or the main memory. Of course we want to make it as easy as possible for you to get your BX system running at fast 133 MHz FSB, so we made a short check list. More on that later.