What Does Northbridge Mean?

The northbridge is one of the two chips, or integrated circuits (ICs), within the chipset on the motherboard. The other chip is called the southbridge. Each chip has a specific set of tasks and communicates between the CPU and external devices through buses.


The northbridge connects the southbridge to the CPU. It is often referred to as the memory controller hub. It handles the faster components on the motherboard, including RAM, ROM, basic input/output system (BIOS), accelerated graphics port (AGP), PCI Express, and the southbridge chip as well as the CPU. It also controls the CPU cache, if it is located on the motherboard.

Techopedia Explains Northbridge

The northbridge plays a vital role in bus speed and is often used as a baseline for establishing the operating frequency for overclocking (the process of running a computer component at a faster processing speed than the manufacturer’s specifications).

Recent developments indicate that the northbridge may be on its way out. Memory controllers are now being integrated onto the processor die in AMD64 processors. The AMD64 architecture is also implemented in Intel’s newer Pentium 4F and Xeon designs. Additionally, the creation of the PCI Express bus has made the accelerated graphics port (AGP) close to obsolete.


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Margaret Rouse

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.