Microsoft warns of slowdowns with the P4 on Windows XP

[markrb]

http://www.theinquirer.net/?article=10037

Glad I have an AMD CPU.

Mark

[dvd2svcd]

Forgive me my stupidity, but what is a Logical Processor? Is it a CPU?

[wmansir]

Originally posted by dvd2svcd
Forgive me my stupidity, but what is a Logical Processor? Is it a CPU?

kind of. With the introduction of Hyperthreading a single P4 can pretend to be a dual CPU system. So even though you only have 1 physical processor the operating system sees two Logical Processors.

[dvd2svcd]

Ahh,ok :). So, how or where can I see if my P4 is using more than one Logical Processor (Which is when the problem occur)?

[wmansir]

Only the latest P4 have Hyperthreading, like 3.0GHZ+ (I think some 2.8Ghz Xeons had it too), and it has to be enabled in the bios.

You can check your system in XP by opening Task Manger (ctr-alt-del) and clicking on the Performance tab. If you have Hyperthreading (or Dual CPUS) you will see two CPU usage graphs.

Here's a picture:

http://www.hothardware.com/reviews/images/p4306ht/httaskmanager.htm

This guy is running 2 Hyperthreading P4, so the sytem sees 4 logical procesors:

http://weblogs.cs.cornell.edu/AllThingsDistributed/archives/000017.html

[dvd2svcd]

Thanks a bundle :D

[int 21h]

Originally posted by wmansir
...Only the latest P4 have Hyperthreading, like 3.0GHZ+ (I think some 2.8Ghz Xeons had it too), and it has to be enabled in the bios...


AFAIK, all the Xeons had it. And, rumor has it that the P4 has always had it, and that the bridges just weren't enabled.

Anyways, anyone who is suffering from this bug in Microsoft's code can download the fix here: http://homepage.ntlworld.com/creamhackered/Q815227_WXP_SP2_x86_ENU.exe