> GPUs aren't really SIMD, they're SIMT (single instruction multiple thread). This might be more confusing than it needs to be. SIMD and SIMT are not mutually

> GPUs aren't really SIMD, they're SIMT (single instruction multiple thread). This might be more confusing than it needs to be. SIMD and SIMT are not mutually exclusive. People commonly think of things like vector registers when they talk about SIMD, and each "thread" in a GPU warp definitely deals with local vector registers. Granted, they may be slices of superwide registers shared by the whole warp, or whatever else, but from the programmer's perspective, that's a valid way to think about it. Put another way, it would be a mistake to think that each lane of a vec4 in a shader gets processed by a separate unit.