"The KK266-R North Bridge provides an option of 133Mhz or 100Mhz FSB CPU's. This allows you to use the newer AMD Thunderbirds with 133Mhz DDR bus speed. A tactic people have used even without a 133Mhz CPU is lower the multiplier and raise the FSB. This gives you the same speed in Mhz but performs alot better. The North Bridge also supports 2x and 4x AGP with a universal slot, so you will not have any problems using almost any current video card. As usual the North Bridge is covered by a green heatsink. On some other Abit and Asus motherboard the North Bridge has a fan but the heatsink is just adequate."
FULL STORY @ ACIDHARDWARE (http://www.acidhardware.com/reviews/iwill/kk266r.shtml)