Incorrect multi-processor count

[Bob Glaser]

My XP Pro setup is on a machine with Dual Xeon Processors.
I noticed recently that some programs when starting, report
4 processors in thier splash screens when starting. When I
started Windows task manager and went to the performance
tab, I noticed four windows for processors. Each of these
windows shows activity. This is something that I noticed
for over a month (with the application splash screen) and
since there wea no need for processor intense work, it was
until now a backburner issue.

My concern here is that those applications that I use that
require multi-processing, may be running ineffeciently due
to this.

Any suggestions other than reinstalling the OS (which would
be three days of work with the application setups required).

 

[Mark Weinreb]

My XP Pro setup is on a machine with Dual Xeon Processors.
I noticed recently that some programs when starting, report
4 processors in thier splash screens when starting. When I
started Windows task manager and went to the performance
tab, I noticed four windows for processors. Each of these
windows shows activity. This is something that I noticed
for over a month (with the application splash screen) and
since there wea no need for processor intense work, it was
until now a backburner issue.

My concern here is that those applications that I use that
require multi-processing, may be running ineffeciently due
to this.

Any suggestions other than reinstalling the OS (which would
be three days of work with the application setups required).

If your Xeon processors support hyperthreading, then what you are seeing is
perfectly normal. XP sees each hyperthreded processor as two processors (but
as one for licensing compliance). So two hyperthreaded processors will be
seen as four processors to applications.

 

[Mike Kolitz]

I'm guessing that your processors support Hyperthreading - which turns one
physical processor into two logical processors.

You can learn more about Hyperthreading here:
http://www.intel.com/technology/hyperthread/index.htm

--
Mike Kolitz MCSE 2000
MS-MVP - Windows Setup and Deployment

Remember to check Windows Update often,
and apply the patches marked as Critical!
http://windowsupdate.microsoft.com

 

[Bob Glaser]

My question then, is why did the two processors show up
as two in the task manager peformance tab for 4-5 months
before switching to showing 4 processors a little over a
month ago?

 

[Mark Weinreb]

My question then, is why did the two processors show up
as two in the task manager peformance tab for 4-5 months
before switching to showing 4 processors a little over a
month ago?

Hyperthreading support was only added to Windows XP fairly recently (within
the last few months, I think). You may only have installed the appropriate
update about a month ago.

 

[Alex Nichol]

My XP Pro setup is on a machine with Dual Xeon Processors.
I noticed recently that some programs when starting, report
4 processors in thier splash screens when starting. When I
started Windows task manager and went to the performance
tab, I noticed four windows for processors. Each of these
windows shows activity.

You have the 'hyperthreading' versions of these processors. Each chip
contains in effect two processors that can act autonomously. SOme
information programs could these individually, others (such as windows
setup deciding how many you are allowed) count chips