randomErr's Journal: What the hell is Hyper-Threading?

Server Briefing Announced last autumn, Intel's Hyper-Threading technology has finally made it to market, courtesy of the latest Xeon processors. Hyper-Threading is a clever way of making a single chip operate like two separate devices without implementing two cores on one die. That, claims Intel, makes for higher performance without having to resort to significantly larger chips or even adding a second processor to the system.

So how does it work? HT is Intel's implementation of a technique known as Simultaneous Multi-Threading (SMT), a technology originally mooted for the cancelled EV8 Alpha processor. It's also going to be implented in IBM's Power5 processor, due 2004. Programmers have long known that some applications will run more efficiently if they're coded into a series parallel tasks, called threads. Modern multi-processing operating systems can then schedule those threads to operate on each of a system's two or more CPUs, just as it schedules the applications and other processes themselves.

Complete Article: theregister.co.uk