AMU 2026 — Computer PYQ

Flynn's Taxonomy classifies computer architectures into four distinct categories based on the number of concurrent Instruction Streams and Data Streams.

To determine which are true parallel processing architectures, let's analyze each category:

1. SISD (Single Instruction, Single Data):

   • This represents a standard conventional single-core processor (von Neumann architecture).

   • It executes a single instruction stream sequentially to manipulate a single data stream.

   • Conclusion: It is not a parallel processing architecture.

2. SIMD (Single Instruction, Multiple Data):

   • A single control unit broadcasts the same instruction to multiple processing elements, where each processing element executes it on different data points simultaneously.

   • Examples include array processors, vector processors, and modern GPUs.

   • Conclusion: It is an explicit example of parallel processing.

3. MIMD (Multiple Instruction, Multiple Data):

   • Multiple autonomous processors simultaneously execute different instruction streams on different data streams.

   • Examples include modern multi-core computers, distributed systems, and supercomputer clusters.

   • Conclusion: It is the most common and powerful example of parallel processing.

4. MISD (Multiple Instruction, Single Data):

   • Multiple processing units execute different instructions on the same single data stream.

   • This is a highly theoretical structure used mainly for fault-tolerance in specialized systems (like flight control backups), rather than speed-driven parallel processing.

   • Conclusion: It is generally not classified as a mainstream parallel processing computing architecture.

Classification Summary Matrix

The architectural taxonomy can be summarized mathematically using the dimensions of Instruction ($I$) and Data ($D$):

Hence, I (SIMD) and II (MIMD) are the clear examples of parallel processing architectures.