Wikipedia
A northbridge or host bridge is one of the two chips in the core logic chipset architecture on a PC motherboard, the other being the southbridge. Unlike the southbridge, northbridge is connected directly to the CPU via the front-side bus (FSB) and is thus responsible for tasks that require the highest performance. The northbridge is usually paired with a southbridge, also known as I/O controller hub. In systems where they are included, these two chips …
Northbridge (computing) - Wikipedia, the free encyclopedia