Pentium 805D has an interesting surprise

[Paul Lussier]

<bmcculley at rcn.com> writes:

> Actually it looks like the newer Xeons (dual and quad cores) don't
> support HT.
>
> I googled and found this comment: 
>
> "Hyperthreading is only on the NetBurst based 50xx Xeons - the Core2
> based 51xx Xeons do not support hyperthreading"
>
> The same is apparently true of the 5300 quad-core Xeon.  So much for
> my hope that the new 3GHz eight-core MacPro would hyperthread to
> give 16 virtual CPUs :-(

How does one tell wether the Xeon is NetBurst 50xx-based, or Core2
51xx-based, or 5300-based?
-- 
Seeya,
Paul