Hyper Threading: Seeing 4 CPUs in Windows XP

[belinus]

Is there anything special I need to do? Windows only sees 2 CPUs, but the BIOS says 4. I know Windows XP supports the additional 2 virtual CPUs since I've seen screen shots but none of thsites say anything about enabling them, etc.

 

[bront]

What version of XP?

As far as I know, XP Pro only supports 1-2 CPUs without additional licencing.

English is phun.

 

[belinus]

XP Pro. I've never seen anything about a per CPU license of an OS.

 

[bront]

All the licences I've gotten for XP here at work have been 1-2 CPU licences. It should say that on your licence when you bought the OS.

What does your licence say?

English is phun.

 

[belinus]

Windows XP Pro's Kernel only does 1-2 Physical CPUs. It is supposed to support the virtual ones since those are not real CPUs.

 

[bront]

Check out Microsoft's website for a fix then. This was an issue on some servers though that Microsoft required an additional licence for the additional CPUs, even though they aren't real CPUs.

XP may not be able to support the extra virtual CPUs, because as far as the OS goes, they are actual CPUs, and the kernal would need code to be able to support more than 2 to do it even virtualy.

English is phun.

 

[belinus]

But then where are people getting Windows XP Taskman shots w/ 4 CPU graphs?

Even Tom's testing of it was on XP.

 

[bront]

Might it have been a server OS? I thought it was with 2000 server?

I don't remember seeing an XP review with Hyperthreading. Please provide a link.

English is phun.

 

[belinus]

Description of the Test system
http://www6.tomshardware.com/cpu/02q1/0203131/dual-04.html

Screen shot of TaskMan
http://www6.tomshardware.com/cpu/02q1/0203131/dual-03.html

Here's another TaskMan shotthat is clearly XP (Luna Interface used)
http://www.whiningdog.net/Reviews/PC/Prestonia18XEON/18Prestonia.htm

 

[bront]

Try e-mailing the authors and asking them then.

English is phun.

 

[imgod2u]

All the NT5.1 versions of windows count physical and logical processors separately. It limits you to a number of physical CPU's but not logical ones. This was in an article on digit-life a while back.