A multi-core CPU (or chip-level multiprocessor, CMP) combines two or more independent cores into a single package composed of a single integrated circuit (IC), called a die, or more dies packaged together.
A dual-core processor contains two cores, and a quad-core processor contains four cores. A multi-core microprocessor implements multiprocessing in a single physical package.
A processor with all cores on a single die is called a monolithic processor. Cores in a multicore device may share a single coherent cache at the highest on-device cache level (e.g. L2 for the Intel Core 2) or may have separate caches (e.g. current AMD dual-core processors).
The processors also share the same interconnect to the rest of the system. Each "core" independently implements optimizations such as superscalar execution, pipelining, and multithreading. A system with n cores is effective when it is presented with n or more threads concurrently.
The most commercially significant (or at least the most 'obvious') multi-core processors are those used in personal computers (primarily from Intel and AMD) and game consoles (e.g., the eight-core Cell processor in the PS3 and the three-core Xenon processor in the Xbox 360).
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