JustujuAI, layer by layer.Open in the interactive map

GPUs & AI accelerators

Chips built to do enormous numbers of simple multiplications in parallel, the core operation of neural networks.

Layer 2 · Compute Hardware · Build and run time · Draft, awaiting expert review, reviewed 2026-10-02

D1 · StoryFor young children and total beginners

Guess first: one genius or a stadium of helpers for a billion sums?

A normal computer brain (a CPU) is like one very clever person doing sums one after another. A GPU is like a stadium full of people each doing one small sum at the same time.

AI needs billions of small sums, so the stadium wins.

Like: One clever person versus a stadium full of helpers.

D2 · PictureFor curious beginners

Neural networks mostly multiply large grids of numbers (matrices). GPUs and other accelerators contain thousands of simple cores and specialised matrix units that do these multiplications in parallel.

They also use lower-precision number formats (16-, 8- or even 4-bit) to fit more maths per second and more numbers in memory.

Each chip maker's software platform lets machine-learning frameworks use the hardware without chip-level code.

Like: A CPU is a few expert chefs; a GPU is a huge team of line cooks all chopping at once.
Where it breaks: Line cooks work independently. GPU cores run the same instruction on different data in lockstep, so work that can't be split evenly wastes most of the team.

D5 · FrontierFor experts

Frontier questions: specialised inference chips versus general-purpose GPUs, how far low-precision formats can go without hurting quality, and whether memory bandwidth rather than arithmetic becomes the permanent bottleneck.

Examples as of 2026-10-13

Sources

  1. Making Deep Learning Go Brrrr From First Principles (Horace He) (2022)
  2. In-Datacenter Performance Analysis of a Tensor Processing Unit (2017-04-16)