FreeBSD on dual core Opterons - stupid buildworld test

[David O'Brien]

On Wed, May 18, 2005 at 11:44:13AM -0700, Astrodog wrote:
> > > > > http://people.fsn.hu/~bra/bl45p/dmesg.boot
> > > > >  Hyperthreading: 2 logical CPUs
> > > >
> > > > So dual-core Opterons report into system as Hyperthreading?
> > > > Uncool.
> > >
> > > What the AMD reps said at a session I attended last year is that
> > > they report as supporting hyper threading, but set another bit to
> > > say that they are actually real cores.  We probably need to find
> > > out what that bit is.
..
> 
> Opteron reports Hyperthreading, because it tries to take advantage of
> the licencing benifit. Keep in mind, HT P4s are counted as a single
> CPU for the most part, in a licence. Opteron may not. By acting as
> though its a HT processor, it gets that same benifit.

Partical truth.  AMD also sets the HTT bit so that legacy OS's (ie, those
released before AMD dual-core) will take some advantage of the 2nd
core(s).

-- 
-- David  (obrien at FreeBSD.org)