XP Pro Supports Dual Processors, what about 2x Hyperthreaded CPU's

[boggsie]

Here is my question. I am lead to believe that Windows XP Pro Supports up to and including 2 Processors. So, most of the boxes where I have seen XP installed with a P4 supporting Hyperthreading, in Task Manager, under Performance, it appears that two processors are there. So, if it is true that XP Pro only supports two processors, what does XP Pro do with a Dual CPU setup with P4 Hyperthreaded chips?

 

[Budman]

Originally posted by: boggsie
Here is my question. I am lead to believe that Windows XP Pro Supports up to and including 2 Processors. So, most of the boxes where I have seen XP installed with a P4 supporting Hyperthreading, in Task Manager, under Performance, it appears that two processors are there. So, if it is true that XP Pro only supports two processors, what does XP Pro do with a Dual CPU setup with P4 Hyperthreaded chips?

XP sees and know about logical cpus,it know hyperthreading is not a real 2nd cpu.

So you can run 2 real cpus (with HT) with XP.

 

[apriest]

Yup, XP Pro runs fine with dual Xeons and HyperThreading. I've built many. I can't speak for Home Edition or Win2K though. I think I remember hearing there were issues...

 

[Canterwood]

XP Home Edition only supports 1 cpu, but it will be be ok with a HT P4. (Knows it only 1 physical cpu)
2K has issues in that it thinks a HT cpu is actually two physical cpu's.
Server 2003 is optimized to work ok with Hyper threaded cpu's.
Anyway, you'll never find a dual P4 system, only dual Xeon's. (Technically they're P4 Xeon's tho')

 

[sm]

XP Pro sees Dual Xeon's as 4 CPU's on the machine I am running

 

[kylef]

Yep. Even though XP Pro supposedly only supports 2 CPU's, dual Xeons show up as 4 CPU's in Task Manager. It's neat-o!

Of course, it's not all that simple in terms of performance, but hey, it looks mighty impressive.