turning hyper-threading off

[Guest]

I can turn hyper-threading off from the bios, but device manager still see it as multiprocessor. The knowledge base says "If the Hyper-Threading feature is disabled in the computer's BIOS, Windows XP may describe the computer as a Uniprocessor PC and may show only a single processor installed in Device Manager.

When Hyper-Threading is enabled in the computer's BIOS, Windows XP automatically upgrades the hardware abstraction layer (HAL) if it must use a multi-processor HAL, and an additional processor or processors may be installed and listed under Processors in Device Manager. The system will prompt you to restart so that the new settings can take effect. "

How do I get device manager to "see" it as a uniprocessor? I'm doing some testing between hyper and non-hyper and I would like the system to be a "real" uniprocessor for the test (being timed).

thanks,
dave

 

[Yves Leclerc]

If HT was turned on when XP was installed, the PC is a "multi-processor"
system. This seems to be the only driver that can not be plug and play. So
when you changed to a single processor (HT off), you may have to re-install
XP.

HT = HyperTheading.

I can turn hyper-threading off from the bios, but device manager still see

it as multiprocessor. The knowledge base says "If the Hyper-Threading
feature is disabled in the computer's BIOS, Windows XP may describe the
computer as a Uniprocessor PC and may show only a single processor installed
in Device Manager.

When Hyper-Threading is enabled in the computer's BIOS, Windows XP

automatically upgrades the hardware abstraction layer (HAL) if it must use a
multi-processor HAL, and an additional processor or processors may be
installed and listed under Processors in Device Manager. The system will
prompt you to restart so that the new settings can take effect. "

How do I get device manager to "see" it as a uniprocessor? I'm doing some

testing between hyper and non-hyper and I would like the system to be a
"real" uniprocessor for the test (being timed).

 

[Guest]

So, would it be correct to assume the opposite is true? I have a laptop that had Windows XP installed on it for me, but the HT was turned off in BIOS. I turned it on, and while I do see two processors in my Device Manager, I do not see two processors in my Task Manager. Also all software made for multi-processing (such as Cakewalk Sonar 3) shows only one processor, and won't let me enable multi-processing capabilities.

Is the fix for this problem to reinstall windows now that my HT is enabled in BIOS?
Thanks so much!!

 

[Carey Frisch [MVP]]

Open Task Manager > Performance tab and from
the Toolbar select: View > CPU History > One graph per CPU.

--
Carey Frisch
Microsoft MVP
Windows XP - Shell/User

Be Smart! Protect your PC!
http://www.microsoft.com/security/protect/

----------------------------------------------------------------------------------------------


| So, would it be correct to assume the opposite is true? I have a laptop that had Windows XP installed on it
for me, but the HT was turned off in BIOS. I turned it on, and while I do see two processors in my Device
Manager, I do not see two processors in my Task Manager. Also all software made for multi-processing (such as
Cakewalk Sonar 3) shows only one processor, and won't let me enable multi-processing capabilities.
|
| Is the fix for this problem to reinstall windows now that my HT is enabled in BIOS?
| Thanks so much!!

 

[Guest]

I've have my Task Manager set this way already (but I double checked just go be absolutely sure.) It actually does not give me the option to choose anything else.

Regardless of the Task Manager, none of my multi-processing software will let me use the multi-processing features. I have a desktop that also runs the software and has HT and it works just fine. The only thing I know is that HT was turned off during installation of Windows XP on my laptop. If I have to reinstall I will, but I'd rather not do that and find out it was in vain.

 

[Zoltan Fekete]

I've have my Task Manager set this way already (but I double checked just go be absolutely sure.) It actually does not give me the option to choose anything else.

Regardless of the Task Manager, none of my multi-processing software will let me use the multi-processing features. I have a desktop that also runs the software and has HT and it works just fine. The only thing I know is that HT was turned off during installation of Windows XP on my laptop. If I have to reinstall I will, but I'd rather not do that and find out it was in vain.

Try this: go to device manager, expand "Computer", right click your
computer, "Update driver", search automatically.

What do you have under the Computer in the device manager ?
For HT it will probably be something like "ACPI Multiprocessor PC", like
on my dual processor desktop, vs. "ACPI PC" that is on my single CPU
notebook.

Best regards,

--
Zoltan Fekete <[email protected]>
Microsoft Certified Professional

YU Spin d.o.o. Novi Sad - http://www.yuspin.co.yu
NetSee Network Utility - http://yuspin.metrohive.net/netsee