A multicore is an architecture design that keeps multiple processors on a single die (chip). A core is nothing but a processor that contains a circuitry to execute instructions. A multi-core processor is a chip that contains two or more cores.The operating system considers each core as a separate processor.

Background

As technology advances chip capacity also increases. This allows placing multiple processors on a single chip. These designs are known as chip multiprocessors (CMPs) as they support single chip multiprocessing. Multi core is widely known as CMP or single chip multiprocessors. The CMP is becoming the preferred method of improving overall system performance.

Hybrid multi-core architecture

Mixing multiple processor types and/or threading schemes on a single package provides a very effective approach for code optimization and specialization. The Hybrid multicore architecture combines unique capabilities into a single functional core. Example: IBM’s Cell broadband engine (Cell).

Flavors of multi-core processors

Multi-core processors come in multiple flavors: two processors (dual core), four processors (quad core) and eight processors (octa-core) configurations. Some configurations are multihreaded; some are not multithreaded.

Dual core processor

A dual-core processor is a chip that contains two cores. It combines two independent processors and their L1 cache memories onto a single chip. Hyper threading technology allows dual core processors to execute up to four threads simultaneously.

The core features of dual core processor are piplelines and cache memory. Each processor has has a block of shared L2 cache. The benefit of having single chip is that it consumes less power than two separate processors would.

Quad-core processor

It is a chip with four separate processor cores. It allows four threads to be processed in parallel. Hyper threading technology allows quad core processors to execute up to eight threads simultaneously.