HT on a dual Xeon system, for real?

[cptgrudge]

I've been looking around for a few days and I haven't found the answer to this yet. If I have a dual Xeon machine and enable hyperthreading on the processors, within Windows XP Pro it will show 4 "processors". Does Windows XP Pro even care about or use the additional virtual processors since it only supports 2 processors in the first place? Would you need to use an MS Server OS to take advantage of this type of setup?

 

[satrow]

I've built a couple of dual Xeon 3.06's in the last few months, based on the ASUS PC-DL.
HT works fine in XPpro. The users have reported no problems, just hugely reduced rendering times.

Andy.

 

[CitrixEngineer]

Windows XP Pro does not use the extra processors - to do that, you need an operating system designed for multiple processors, with a special HAL, such as Windows 2000 Advanced Server (NOT regular server, which only recognises 2 processors), or Linux.

 

[satrow]

Windows XP Professional DOES use use 2 CPU's!

*** Supports up to 4 gigabytes (GB) of RAM and up to two symmetric multiprocessors.

http://www.microsoft.com/windowsxp/pro/evaluation/features.asp

***

Which is what I used on the above systems.

 

[CitrixEngineer]

Maybe, but it won't use MORE than 2

I would guess that this also applies to virtual processors.

You could prove this by running Task Manager and seeing a) how many processors are listed and b) how many are being used.

You could also use perfmon for more detailed results.

HTH