JNTU B.Tech III COMPUTER ORGANIZATION AND OPERATING SYSTEMS Previous Question Paper (July/August - 2023 - R13)

A Reduced Instruction Set Computer (RISC) is a processor architecture design philosophy that emphasizes the use of a small, highly optimized set of simple instructions. By executing instructions in a single clock cycle through techniques like pipelining, RISC architectures achieve higher performance despite requiring more instructions to complete complex tasks. Key characteristics include a load/store architecture, a large number of general-purpose registers, and fixed-length instruction formats to simplify decoding.

The primary difference between multiprocessors and multicomputers lies in their memory architecture and communication mechanism:

• Memory Architecture: Multiprocessors utilize a shared memory model where all processors share a single global address space. In contrast, multicomputers use a distributed memory model where each processor has its own local, private memory that is not accessible by other processors.
• Communication: In multiprocessors, communication between processors occurs through shared variables in the common memory. In multicomputers, processors communicate by explicitly passing messages over an interconnection network.
• Scalability: Multiprocessors are generally limited in scalability due to memory contention and bus bottlenecks as the number of processors increases. Multicomputers are highly scalable because each processing node operates independently with its own memory, avoiding centralized bottlenecks.