Definition: GPU

(Graphics Processing Unit) A programmable processor specialized for rendering 3D images on a Windows computer. NVIDIA is the leader in the field by a large margin (see NVIDIA). However, AMD and Intel also make GPUs, and Apple, Qualcomm and ARM integrate GPU circuits into mobile devices.

Graphics circuitry can be included with other functions in the PC's chipset or even on the CPU chip itself. However, for gamers, the stand-alone graphics card with a GPU that plugs into a PCI Express (PCIe) slot on the PC motherboard is essential. See chipset.

GPUs are all about parallel operations. Although it is also used for 2D data as well as zooming and panning the screen, a GPU is essential for rendering 3D animation. The more sophisticated the GPU, the higher the resolution and the faster and smoother the motion. See graphics pipeline.

The Engine Behind AI and Crypto
A GPU is a "math machine" that performs huge amounts of simple calculations simultaneously making it ideal for AI applications that require trillions of computations (see neural network and AI training passes). GPUs are also used to mine certain cryptocurrencies (see GPU mining).

The Streaming Multiprocessor (SM)
An NVIDA GPU can manage more than a hundred streaming multiprocessors (SMs), which are its primary processing units. For example, the GPU in NVIDIA's RTX 4090 graphics card controls 128 SMs each with 128 CUDA cores for a total of 16,384 CUDA arithmetic units. For non-NVIDIA GPUs, Compute Units (CU), Workgroup Processors (WGP) and Xe Cores are equivalent to the SM. See CUDA.

Ray Tracing Engine
A GPU may also include hardware to accelerate ray tracing, which simulates a light source falling on objects to create bright areas and shadows. Fast ray tracing enhances realism and has become mandatory for serious gaming (see ray tracing).

GPUs Are Often Integrated With the CPU

Introduced in 2012, AMD's Trinity chip integrated a GPU with memory (DDR3) and two dual-core x86 CPUs, each with their own L2 cache (see x86, L2 cache). (Image courtesy of Advanced Micro Devices, Inc.)

GPU and Everything Else

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

Graphics Evolution in a Windows PC

On the left is the evolution of graphics circuits with 7 being the latest. On the right is performance with 1 being the fastest. Gamers plug in the fastest GPU card they can afford, and high-end graphics can cost more than the entire PC (see RTX).

Blame It on the Gamers!

Had gaming with 3D images not been such a force in the 1990s, NVIDIA would not have been compelled to make video cards with GPUs that would get faster every year. The enthusiasm for 3D games was singularly responsible for AI to flourish by the 2020s. See NVIDIA.