Flynns taxonomy

Flynn's taxonomy is a way to classify computer architectures based on the number of instruction streams and data streams available.

SISD: Single instruction stream single data stream

The classic PC with one processor that do one thing at a time.

SIMD: Single Instruction Multiple Data

One thread with wide execution data. Example x86 SSE/AVX.

MISD: Multiple instruction streams, single data stream

MIMD: Multiple Instruction Multiple Data

Multiple independent threads. Example multicore CPUs.

SIMT: Single Instruction Multiple Thread

Multiple lockstep threads. Ex GPUs. An instruction is issued for an entire group of threads at the same time. Thread carriers out the operation on it's own arguments.

SPMD: Single program, multiple data streams

MPMD: Multiple programs, multiple data streams