Arithmetic Intensity
The ratio of compute work (FLOPs) to memory movement (bytes)
Fundamentals
In plain English
How many math problems you solve per page of the textbook you turn. If you solve 100 per page, you work fast. If you turn a page for just 1 math problem, you spend all your time turning pages.
Technically
The ratio of floating-point operations to memory access (FLOPs/byte). In transformer inference, prompt prefill achieves >100 FLOPs/byte (compute-bound), while autoregressive token generation achieves <2 FLOPs/byte (memory-bound).