In message <Pine.NEB.4.58.0309200758350.18895@rapture.immanent.net>, Frederick 
Bruckman writes:
>I have a Compaq W8000, 2.2GHz, which does have an option in the CMOS
>utility to enable hyperthreading, but no matter -- NetBSD 1.6ZC as of
>yesterday still sees only one processor (feature list shows HTT, BIOS
>has been upgraded to the latest, 1.27).

Same situation here.  Motherboard is a Gigabyte 8EGXR, with latest BIOS.
It has options for MPS version and enabling hyperthreading, but no joy.

-s