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 must-have, 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), but is not as fast as the separate GPU card, which can cost as much or more than the entire computer. See PCI Express.

While motherboard GPUs share main memory with the CPU, high-end GPU cards have many gigabytes of their own video memory (see GDDR).

A GPU is all about performing 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.

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 enhances realism and has become mandatory for serious gaming (see ray tracing).

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

GPU and CPU

AMD's Trinity chip integrates a GPU with four cores of x86 processing and DDR memory controller. Each x86 section has a dual-core CPU and cache (see L2 cache). (Image courtesy of Advanced Micro Devices, Inc.)

GPU and Everything

In 2020, Qualcomm introduced the Snapdragon 888 system-on-chip (SoC). Along with a GPU, this single chip does just about everything. See Snapdragon and SoC.

Graphics Evolution

In early PCs, the graphics was a separate plug-in card. From top to bottom (1 to 7) is the evolution of graphics circuits in a PC. The fastest graphics (#6) uses multiple GPU, and three high-end graphics cards can cost much more than the computer itself.