Author: Vincent Diepeveen
Date: 10:58:43 11/17/02
Hello,
If i read the below section of the intel programming guide very well,
then i interpret that as:
a) only the Xeon MP has hyperthreading and not the normal P4s,
not even P4s sold as Northwoods.
b) even the Xeon MP you should not assume that it supports hyper
threading. In fact something that gets sold as Xeon MP you should
still not assume that it supports hyper threading, but instead
one must assume that only after specifically questionning the cpu
whether it can do it.
Intel IA-32 programming manual. Page 247 (of 780):
"
7.6.1 Implementation of Hyper-Threading Technology in IA-32 Processors
Intel's Hyper-threading Technology was introduced into the IA-32 architecture
in the Intel Xeon processor MP and in the later steppings of the Intel Xeon
processor. Both of these processors implement Hyper-Threading Technology with 2
logical processors per physical processor. When reading the following sections
(and other sections in this book that refer to this technology), assume that all
references to the implementation of Hyper-Threading Technology in the Intel Xeon
processor MP also apply to those later steppings of the Intel Xeon processor
that implement Hyper-Threading Technology.
Intel recommends that software not rely on IA-32 processor names to determine
whether a processor supports Hyper-Threading Technology; but instead, it should
use the CPUID instruction as described in Section 7.6.5, "Detecting
Hyper-Threading Technology".
"
Vincent
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.