Uniprocessors to Multiprocessors

UNIPROCESSORS TO MULTIPROCESSORS

Uniprocessor :

- A type of architecture that is based on a single computing unit. All operations (additions, multiplications, etc ) are done sequentially on the unit.

Multiprocessor :

- A type of architecture that is based on multiple computing units. Some of the operations ( not all, mind you ) are done in parallel and the results are joined afterwards.

There are many types of classifications for multiprocessor architectures, the most commonly known would be the Flynn Taxonomy.

MIPS (originally an acronym for Microprocessor without Interlocked Pipeline Stages) is a reduced instruction set computer (RISC) instruction set architecture (ISA) developed by MIPS Technologies.

The power limit has forced a dramatic change in the design of microprocessors. Since 2002, the rate has slowed from a factor of 1.5 per year to a factor of 1.2 per year. Rather than continuing to decrease the response time of a single program running on the single processor, as of 2006 all desktop and server companies are shipping microprocessors with multiple processors per chip, where the benefit is oft en more on throughput than on response time. To reduce confusion between the words processor and microprocessor, companies refer to processors as “cores,” and such microprocessors are generically called multicore microprocessors.

Hence, a “quadcore” microprocessor is a chip that contains four processors or four cores. In the past, programmers could rely on innovations in hardware, architecture, and compilers to double performance of their programs every 18 months without having to change a line of code. Today, for programmers to get significant improvement in response time, they need to rewrite their programs to take advantage of multiple processors. Moreover, to get the historic benefit of running faster on new microprocessors, programmers will have to continue to improve performance of their code as the number of cores increases.