A multi-core microprocessor ( or chip-level multiprocessor, CMP) is one that combines two or more independent processors into a single package, often a single integrated circuit (IC). A dual-core device contains two independent microprocessors and a quad-core device contains four microprocessors. A multi-core microprocessor implements multiprocessing in a single physical package. 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') The processors ...