Accelerator
Beginner
A part of a chip built to do one kind of job, such as video or AI, much faster and with much less energy than a general-purpose processor.
Novice
A block built for one kind of work, such as graphics (a GPU), neural networks (an NPU), video or encryption, that the main processor hands jobs to. It saves energy by skipping the work of fetching and decoding general-purpose instructions, using only as many bits as the job needs, doing many operations at once and keeping data in nearby memory.
Expert
Its benefit is limited three ways: by the share of the work it can take on (Amdahl’s law), by the cost of handing work over and collecting results, and by memory bandwidth. Once arithmetic is cheap, memory usually takes most of its area and power.