PC Hardware in a Nutshell, 3rd Edition

CPU speed support

A chipset that supports a particular CPU may support all or only some of the speeds at which that processor is available. In general, faster CPUs require faster chipsets, so you might imagine that a chipset rated to handle the fastest version of a particular CPU could also handle slower versions of that CPU. That’s not always the case, however. Modern motherboards accommodate different processor speeds by varying two settings, Front Side Bus (FSB) speed and CPU multiplier:

FSB speed

FSB speed (also called host bus speed) specifies the speed at which the CPU communicates with the chipset. All sixth-generation and later chipsets support an FSB that runs at 66 MHz or faster, sometimes much faster. Early sixth-generation Intel chipsets use a 66 MHz FSB to support the Celeron and Pentium II processors. Later sixth-generation Intel chipsets use the 66 MHz and 100 MHz FSB to support Celeron, Pentium II, and Pentium III processors, and the 133 MHz FSB to support later Pentium III variants.

AMD Athlon chipsets introduced the concept of the double-pumped FSB, which transfers data on both the rising and falling sides of the clock pulse. Early Athlon chipsets supported the 66 MHz FSB double-pumped to 133 MHz, and the 100 MHz FSB doubled-pumped to 200 MHz. Later Athlon chipsets added support for FSB speeds of 133/266 MHz, 166/333 MHz, and 200/400 MHz.

Intel introduced the quad-pumped FSB in its seventh-generation Pentium 4 chipsets. First-generation Intel Pentium 4 chipsets ...