Definition: GPU

(Graphics Processing Unit) A programmable processor specialized for rendering all images on the computer's screen. A GPU provides the fastest graphics processing, and for gamers, the GPU is a stand-alone card plugged into the PCI Express (PCIe) bus. GPU circuitry can also be part of the motherboard chipset or on the CPU chip itself (see diagram below). See PCI Express.

A GPU performs parallel operations. Although it is used for 2D data as well as for zooming and panning the screen, a GPU is essential for smooth decoding and rendering of 3D animations and video. The more sophisticated the GPU, the higher the resolution and the faster and smoother the motion. GPUs on stand-alone cards include their own memory, while GPUs built into the chipset or CPU chip share main memory with the CPU (see GDDR).

Ray Tracing Engine
GPUs may also include hardware to accelerate ray tracing, which simulates a light source falling on objects resulting in bright areas and shadows. Fast ray tracing greatly determines realism in video games and has become mandatory for serious gaming (see ray tracing).

The Engines Behind AI and Crypto
Because GPUs perform parallel operations on multiple sets of data, they are widely used for scientific and AI applications as well as mining certain cryptocurrencies (see AI and crypto mining). Supercomputers may have thousands of GPUs in addition to their CPUs (see GPGPU). See graphics pipeline and multi-GPU.

Graphics Hardware Locations

In a PC, graphics rendering originally took place in the CPU. Over time, functions were offloaded to separate circuits and then to GPUs either in separate cards, the motherboard chipset or the CPU chip itself. See display adapter, integrated graphics and integrated GPU.

An Integrated GPU

This Trinity chip from AMD integrates a sophisticated GPU with four cores of x86 processing and a DDR3 memory controller. Each x86 section is a dual-core CPU with its own L2 cache. (Image courtesy of Advanced Micro Devices, Inc.)

Lots of GPUs for Crypto Mining

In 2018, Asus introduced its H370 Mining Master motherboard with support for 20 graphics cards via USB riser cables. See Bitcoin miner. (Image courtesy of ASUSTeK Computer Inc.)