What is chip multithreading?
Chip multithreading (CMT) is one way to increase performance through parallel processing. It is the ability of the microprocessor to handle multiple hardware threads of execution as well as handle multiple software threads.
The best way to achieve CMT is through Chip Multiprocessing (CMP), a technology developed by Sun Microsystems. The core feature of the technology is to duplicate the entire processor core along with most of its subsystems and place them on a single silicon chip. This can be achieved by co-packaging two modified processors with additional logic circuitry that allows them to behave exactly like a single dual-core chip.
A big advantage of CMP is its compatibility with previous generations. This allows a CMP processor to fit into an existing computer setup and multiply the number of processors in the system. As the number of processor cores increases, so does processor validation. There is one drawback to this technology, however. Multiplying the number of processors increases the number of transistors exponentially, which takes up more space, is more expensive, and causes problems with heat dissipation.
Chip multithreading is a parallel processing application. It can be thought of as software multithreading, where multiple processor activities can be performed in a single process. The only difference is that CMT is hardware based, so the processor handles the various threads instead of the software. The decisive advantage over older processor technologies is an improved throughput.