How to enable Hyperthreading in Windows 2003?

[Cooky]

I have a server w/ Xeon CPU and Windows 2003 Standard.

After enabling Hyperthreading in BIOS, I now see two CPU's under Hardware Device list in Win 2003.

However, when I launch the Task Manager, the Performance tab still shows only one CPU.

What do I need to do to make it show both logical CPU's?

 

[yinan]

Are you sure the window is maximized? I have never had this issue before.

 

[Cooky]

Sorry, what did you mean if the window is maximized?

I've never seen this either...

 

[Ratman6161]

Look in the device manager and look at the entry under "computer" . It should say "ACPI Multiprocessor PC" but probably doesn't at the moment (probably says Uniprocessor PC). If hyperthreading was not enabled at the time you installed the OS, then the installation would have given you the single processor Hardware Abstraction Layer (HAL).

Its sometimes possible to update the driver for the Computer entry and force it to use the Multiprocessor HAL - but you are taking your chances. Since this is a server is there anything critical on it?

The other thing is that for most things, hyper threading really doesn't do much anyway so unless you are running a workload that actually benefits from it, it may be safer to leave it alone.

 

[bsobel]

Originally posted by: Cooky
I have a server w/ Xeon CPU and Windows 2003 Standard.

After enabling Hyperthreading in BIOS, I now see two CPU's under Hardware Device list in Win 2003.

However, when I launch the Task Manager, the Performance tab still shows only one CPU.

What do I need to do to make it show both logical CPU's?

Did you change the view in taskman to one graph per cpu? It defaults to combined.

 

[C1]

Working on a Pentium M notebook that doesnt have the Performance Monitoring application installed. However, as I recall, from Administrative Tools/Computer Management open the performance monitoring application. There will be a menu that allows adding/deleting the various available processes for monitoring. You should find that you are able to add CPU 1 (ie, now have CPUs 0 & 1) and at that time you can set up to monitor separately each CPU's usage.

Concerning Hyperthreading - when Im doing video work (such as compressing, extracting, viewing, copying, file transfers, etc. concurrent processes) having hyperthreadng makes a whale of a difference.

 

[bsobel]

The other thing is that for most things, hyper threading really doesn't do much anyway so unless you are running a workload that actually benefits from it, it may be safer to leave it alone.

On average hyper threading adds about another 10% processing headroom, you generally want it on unless you have some pretty specific workloads.

 

[C1]

bsobel is correct (ie, more accurate). Hyperthreading can make a noticeable difference (I like to think as much as 15% at least for what I was doing). At the time I was using a 3.06 P4 to concurrently compress seven movie files, while ripping two DvDs while watching a movie (digital file using PDvD) while transfering files (one drive to another). Both CPUs were registering 80-90% with an occasional bump to 100%. The RAMBUS was so hot (seemed to burn my finger) that for safety I put my giant box house fan blowing on the whole side of the machine (side cover off of course) which helped immensely.

 

[Cooky]

This is a lab server that handles AD, DHCP, and Cisco ACS for AAA service.
We've seen it peg to 100% CPU cycle, which is why I'm trying to enable hyperthreading.

I'll see if it's listed as "ACPI Multiprocessor PC" or "uniprocessor" when I go into work tomorrow.
No I didn't change the taskman to one graph per cpu...it always does that for me by default for all the other servers though...

Thanks for everyone's response.