Subject: Re: hyperthreading on 2.0; no way to get it to work with my hardware.
To: None <>
From: Christos Zoulas <>
List: tech-smp
Date: 12/30/2004 04:18:42
In article <>,
okay_awright <> wrote:
>ATT: this message has already been posted on netbsd-help on 12/27/04 
>w/out any answer yet
>hi everyone,
>this a relatively common question and i hope easily solvable.
>I have a NetBSD 2.0 (release, updated from a 1.6.2) system running on an
>Asus P4V8X-X (latest bios) with an Intel Pentium 4 2.40A. This is only a
>workstation but I really wanted to get hyperthreading support (and
>that's why i moved from 1.6.2 release to 2.0 release).
>Back to the problem in itself: no matter which modifications i could
>make in my kernel configuration file, i can't get hyper-threading support.
>In the enclosed part is my current kernel conf file, everything works as
>expected but SMP.
>Activating either MPBIOS or MPACPI alone doesn't help (MPBIOS hangs the
>Just to be sure I used the plain GENERIC.MP file (mine was originally
>made for 1.6.1 and updated) just slightly modified (with MPACPI and
>acpi0 on) but i get the same result: no usable second "virtual" processor.
>My motherboard BIOS is an AMIBIOS; the only options i can customize
>regarding hyperthreading support are the MPS (1.1 versus 1.4; 1.4 is
>selected) and ACPI (2.0 or not; 2.0 is selected) revisions in use.
>Nothing much but dmesg shows me that the processor is already HTT ready.
>may someone help me; i'm clueless. If one could take some time analyzing
>the configuration file or giving me some advices...

The hyperthreading support is found in the ACPI bios. From
the looks of it, your processor supports hyperthreading but the bios
does not advertise it. There is either a bios setting that you have not
found, or this is a limitation in your bios. There could be an updated
bios available that has this feature. You might also want to try to
boot windows to see if it sees the hyperthreaded processor.