Re: Double CPUs or not?

Xiaopeng wrote:
> My OS is WindowsXP Home Edition. I see two cpus under device manager
> but the task manager only shows one. Does my computer really have two
> cpus? If it does, why the second one is not working?
>
> Thanks.

Last time i checked, WinXP Home did not have support for SMP (Symmetric
Multi-Processing). But, It does have support for Intel's so-called
hyper-threading technology. If you are using a Pentium 4 with
hyper-threading technology, this may be why there are 2 processors
showing up (I say MAY BE. I don't use Intel processors, so I wouldn't
know.) I think AMD has a similar technology on their 64-bit processors
(which, just like the Pentium 4, I have never used, so i'm not sure).
If your processor fits either description, this may be why you're
seeing 2 processors. also, since still very few applications support
Hyper-Threading, or whatever AMD calls their equivalent, this may be
why the second is not working.

I'll say it again: I'M NOT SURE, but this is MOST LIKELY the case, as i
cannot think of anything else that would cause this

"Pandora Xero" <> wrote in message news:<cfh8o5$>...
> Xiaopeng wrote:
> > My OS is WindowsXP Home Edition. I see two cpus under device manager
> > but the task manager only shows one. Does my computer really have two
> > cpus? If it does, why the second one is not working?
> >
> > Thanks.
>
> Last time i checked, WinXP Home did not have support for SMP (Symmetric
> Multi-Processing).

This is true. Only XP Pro supports dual processor systems.

> But, It does have support for Intel's so-called
> hyper-threading technology. If you are using a Pentium 4 with
> hyper-threading technology, this may be why there are 2 processors
> showing up (I say MAY BE. I don't use Intel processors, so I wouldn't
> know.) I think AMD has a similar technology on their 64-bit processors
> (which, just like the Pentium 4, I have never used, so i'm not sure).
> If your processor fits either description, this may be why you're
> seeing 2 processors. also, since still very few applications support
> Hyper-Threading, or whatever AMD calls their equivalent, this may be
> why the second is not working.
>
> I'll say it again: I'M NOT SURE, but this is MOST LIKELY the case, as i
> cannot think of anything else that would cause this

I am using an HT P4 right now. It shows up as 2 processors in DXDIAG.
If you need to, you can disable it in the BIOS. Some programs will not
run with HT enabled, like games. For example, Jedi Knight 2 didn't
work until I got a patch with HT support. Also, applications that have
licensing per processor may require 2 licenses for HT.