Since its introduction nearly three years ago, Intel's 440BX chipset has made a significant impact on the motherboard market. In an era of constantly evolving technology, the 440BX has become the mainstay of motherboard producers and consumers alike. Even the i820 chipset, thought to be a replacement for the aging 440BX, ended up being devastated by the little chipset that could: the BX. Plagued with an RDRAM-only memory system after the SDRAM enabling MTH failed, i820 motherboards were quickly forgotten by both consumers and manufacturers, only to be replaced by long lasting BX motherboards.
While the longevity of the 440BX cannot be questioned, the sub par 100 MHz front side bus speed of the BX chipset proved to be a performance limiting factor to professionals and overclockers alike. On the professional side of things, the 100 MHz FSB provides a bottleneck for essentially all system operations. For overclockers, the 100 MHz FSB limit prevented any overclocking of the clock locked Pentium chips.
Luckily, even early BX based motherboards provided a solution to this problem. By setting a few jumpers, or in some cases just pushing a few keys, 440BX based motherboards were able to surpass the Intel suggested speed limit and push the boundaries of FSB speeds. Many BX based motherboards allow for not only the coveted 133 MHz FSB speed, but even higher FSB speeds. The longevity of the 440BX only served to enhance this overclocking option, as good board designs became more and more refined.
It has been shown time and time again that a BX based motherboard running at a front side bus speed of 133 MHz produces the fastest possible motherboard solution. Even the recently announced i815 chipset from Intel proves to be no match for a BX at 133 MHz, even though it officially supports the 133 MHz FSB rating.
The problem with a 440BX running at 133 MHz is obviously not speed: there is plenty of that. Unfortunately, the problems arise from the interaction of components to the motherboard at this non-speced speed. Items such as PCI bus dividers, memory, and AGP dividers are all potential road blocks, preventing 133 MHz operation. Recent months have seen the PCI bus divider and memory problems vanish, leaving only the 2/3 AGP divider standing between you and system bliss. Fortunately, AnandTech is here to help you. To begin, let's investigate why some of the previous problems have disappeared.