what is a north bridge on a video card?

Answer 1

The "North Bridge" is not on the video card it is a component of the chipset..the embedded logic chip on the motherboard that handles communications between the CPU,pci cards, memory etc. Normally the chipset is divided into the North Bridge and the South Bridge. The "North Bridge handles communication with the CPU, memory, and video card(agp only) the South Bridge handles communication with the pci bus, the usb bus, the real time clock, and others.. These are guidelines only.. each manufacturer can decide what their chipset will handle. You can see more here..
http://whatis.techtarget.com/definition/0,,sid9_gci750600,00.html

HTH,
Keith