OT: dual-core or 64 bit?

[Jonathan Berry]

On 1/30/07, David Fletcher <fc at fletchersweb.net> wrote:
> On Sunday 28 January 2007 22:07, Jonathan Berry wrote:
> > On 1/28/07, Mick Mearns <off_by_1 at yahoo.com> wrote:
> > > Hi list;
> > >  this is off topic.
> > >
> > > I was wondering which is better a dual-core x86 cpu or an x64 cpu?
> > > Which is actually faster/better in "normal" use?
> > > How about installation problems and hardware cost?
> > >
> > > I am not planning any upgrades just yet but am curios.
> >
> > Why not get a dual-core x86_64 CPU?  All the AMD dual-core chips are
> > 64-bit and Intel's Core 2 Duo is 64-bit.  Personally, I like AMD
> > better.  There is really no reason to get a 32-bit only CPU anymore.
> > If you don't want to run 64-bit yet, you can still run 32-bit just
> > fine.  And a 64-bit installation gives you the choice to run both.
> >
> > Jonathan
>
> If the List doesn't mind me staying off topic (it's closer to topic than
> servicing a Chevy pickup gearbox I think ;-) ):- Next time I build a new
> computer I'd like to be sure that I can run a Xen kernel with full
> virtualisation. Then when I occasionally need to poke a little finger into
> the Dark Side I can do so without having to shut down and reboot, and keep
> the damned thing backed up so I don't ever need to do a fresh install again.
>
> As I Understand It, if I go for an AMD chip I need to be sure to buy one that
> incorporates technology called Pacifica. Only thing that's troubling me about
> this is, I can't find any mention of Pacifica in connection with AMD chips in
> the component shops.
>
> Also, I believe I can't do it on this P4 computer because it can only do what
> is called paravirtualisation, requiring hooks to be added to the guest OS.
> Which is probably why I could run the 98SE installation CD OK when I played
> with it but it wouldn't boot.
>
> So, List, is the little bit I think I know about virtualisation correct?

Yeah, that sounds like what I have heard about the subject.

> Are there chips available now that have Pacifica (such as the AMD Opterons) or
> are they not out yet?

They are out.  There has not been as much talk about it for some
reason.  I have been surprised at that.  But you want any Socket AM2
AMD CPU (which is the newest) or I think Socket F is the other new
socket (I think for the Opteron class CPUs ?).  Socket 939 and 940
CPUs do not have Pacifica support (not sure what its official name is
now).  On the Intel side, I think all the Core series CPUs have
whatever Intel calls its virtualization extensions.  I'm not sure if
they migrated that back to any of the P4/PD based chips or not.

I too would like to play around with this.  But doing so would require
a new CPU, motherboard, and memory (as the AM2 socket moves to DDR2
RAM) at least.  I'll probably wait at least for the 65 nm AMD chips to
come out before I head down that route.  But has anyone tried this?
Running Windows (or really any unmodified guest) with Xen using the
hardware virtualization extensions?  If so, how did it go?

Jonathan