Hyper-threading

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Hyper-threading is Intel's term for its simultaneous multithreading implementation first appearing in February 2002 on its Xeon server processors and in November 2002 on its Pentium 4 desktop CPUs. Later, Intel included this technology in Itanium, Atom, and Core 'i' Series CPUs, among others. Intel's proprietary HT Technology is used to improve parallelization of computations performed on PC microprocessors. For each processor core that is physically present, the operating system addresses two virtual or logical processors, and shares the workload between them when possible. The main function of hyper-threading is to decrease the number of dependent instructions on the pipeline. Hyper-threading requires not only that the operating system support multiple processors, but also that it be specifically optimized for HTT, and Intel recommends disabling HTT when using operating systems that have not been optimized for this chip feature.