Ars Technica on Hyperthreading
radiokills writes "Ars Technica has a highly-informative technical paper up on Hyper-Threading. It's a technical overview of how simultaneous multithreading works, and what problems it will introduce. It also explains why comparing the technology to SMP is Apples to Oranges, in a sense. Starting with the 3 GHz Pentium 4, this tech will be standard in Intel's desktop lines (it's already in the Xeon), so this is important stuff."
The company that now owns the name Cray does something very much like this on a fairly grand scale on its own architecture, the MTA (Multi-Threaded Architecture). Here, each processor switches between 128(!) hardware threads to take advantage of the sort of concurrancy you can get for waiting for memory access, etc.