Northbridge (computing)

Northbridge (computing)

The northbridge has historically been one of the two chips in the core logic chipset on a PC motherboard, the other being the southbridge. Increasingly these functions have migrated to the CPU chip itself, beginning with memory and graphics controllers. For Intel Sandy Bridge and AMD Fusion processors introduced in 2011, all of the functions of the northbridge reside on the CPU. When a separate northbridge is employed in older Intel systems, it is named memory controller hub (MCH) or integrated memory controller hub (IMCH) if equipped with an integrated VGA.

Separating the different functions into the CPU, northbridge, and southbridge chips is due to the difficulty of integrating all components onto a single chip. In some instances, the northbridge and southbridge functions have been combined onto one die when design complexity and fabrication processes permitted it; for example, the Nvidia GeForce 320M in the 2010 Macbook Air is a northbridge/southbridge/GPU combo chip.