Flynn taxonomy

Classification	instruction flow	data flow	representative architecture	features
SISD	single instruction	single data	by Neumann	Single control unit, executing instructions sequentially A single processor, processing a set of data at a time Typical von Neumann architecture
SIMD	single instruction	multiple data	vector processor	A single control unit broadcasts a command Multiple processors simultaneously execute the same instruction on multiple sets of data Efficiently handle tasks that require performing the same operations on large datasets
MISD	multiple instructions	single data	no widely used architecture	Theoretical classification, no practical application
MIMD	multiple instructions	multiple data	supercomputer	Multiple control units that can execute different instruction streams Multiple processors can perform different operations on different data sets at the same time Efficient execution of various types of parallel tasks

It can be seen that SISD and SIMD architectures consider issues from a single control unit and single/multiple processor angles, and have strong centralized control. The MIMD architecture has the characteristics of distributed control, and multiple control units can execute different tasks in parallel, which is more suitable for complex applications.

In fact, modern computer systems have combined these architectures to form a hybrid architecture. For example, the pipeline of modern CPU also has the characteristics of SIMD; the parallel structure of MIMD is also used in GPU for graphics processing. Therefore, the framework provided by the Flynn taxonomy helps us understand computer architecture at a more fundamental level, which is the cornerstone of mastering this knowledge.

The Flynn taxonomy takes the combination of different instruction streams and data streams as the basis for classifying computer structures, and obtains four basic architectures. These four structures cover a wide range of computer architectures from early to modern times, and are an important tool for understanding the development of computer architectures.