Originally posted by: Rafael
It's the comunication between the northbridge and southbridge.
Raf
Yep,
Rafael is right. It's basically a dedicated high speed connection between the Northbridge and Southbridge of the chipset. In the "olden days"

, the two components were connected via the PCI bus. This connection method had very limited bandwidth, and it left very little for the remaing PCI peripherals. As the chipsets and CPU's got faster and faster and started utilizing things like high speed DDR/RDRAM memory, the NB to SB connection became more and more important. So, as a result, most modern chipsets use a dedicated connection now between the two components, and leave the PCI bus to the peripherals. I hope that explains it for you...
