single or dual processor 2663

On Monday 02 October 2006 16:09, David L. Johnson stood up and addressed the mbuttes incomp.os.linux.miscas follows...:

All the latest Intel Pentium 4 and Xeon processors feature hyperthreading. This is a technique intended to speed up the Netburst architecture, which had very long pipelines - although hyperthreading now also exists on the latest Itaniums - by making use of extra registers so that one physical processor emulates two virtual ones.

If the BIOS has hyperthreading enabled and the operating system is running an ACPI interpreter, then a Pentium 4 or Xeon will show up and work as if it were two independent CPU's, provided that the kernel supports synchronous multi-processing, of course.

In physical SMP systems with P4 or Xeon processors, the kernel should also have symmetric multi-threading support enabled so as to balance the load more adequately between hyperthreaded siblings and physical CPU's.

Note 1: Most 2.4 kernels do not distinguish between hyperthreading and physical SMP systems. You'll need a 2.6 kernel for that.

Note 2: AMD processors do not have hyperthreading. Intel uses the abbreviation HT for hyperthreading, while AMD uses it for the hypertransport bus, which is an entirely different thing, albeit that it also relates to multiprocessor systems.

-- With kind regards,

*Aragorn* (registered GNU-Linux user #223157)