JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III ADVANCED COMPUTER ARCHITECTURE Previous Question Paper (February - 2022 - R18)

A Multiprocessor is a computer system that employs two or more CPUs within a single computer system. These processors share a common main memory and I/O devices, and are controlled by a single operating system. The key characteristic is the shared address space, which allows processors to communicate through shared memory variables. Synchronization is typically managed using hardware-level primitives like semaphores or locks.

A Multicomputer consists of multiple independent computers, often referred to as nodes, connected via an interconnection network. Each node has its own local memory and I/O system, and runs its own operating system. Communication between nodes occurs exclusively through message passing over the network. Because there is no shared memory, multicomputers are generally more scalable than multiprocessors but require explicit software management for data distribution and inter-processor communication.

Multi-vector computers are high-performance systems designed to process long vectors of data using vector instructions. They typically feature multiple vector processors, each capable of performing arithmetic operations on entire arrays of data in a pipelined fashion. These systems exploit data-level parallelism by overlapping the execution of multiple vector operations, often utilizing a shared memory architecture to feed the high-bandwidth requirements of the vector units.

SIMD (Single Instruction, Multiple Data) computers represent an architecture where a single control unit broadcasts a single instruction to multiple processing elements (PEs). Each PE executes the same operation simultaneously on different data elements stored in its local memory. SIMD is highly efficient for data-parallel applications, such as image processing or scientific simulations, where the same transformation is applied across a large dataset. Modern implementations often include GPU architectures that utilize massive SIMD arrays to achieve high throughput.