Hyperthreading on Pentium4

[FTG]

Hi,

I have a Pentium 4 HT 2.6Ghz cpu. When I was using XP, the task manager displayed 2 cpu graphs, showing that Hyperthreading was active. But now in Windows 7, I only see 1 cpu graph. I thought Windows 7 supports hyperthreading ?

The only thing I might have possibly done wrong, was that I disabled HT in the BIOS when I installed Windows 7, only remembering to turn it on in the BIOS after installation.

Can someone with a Pentium4 HT cpu confirm that hyperthreading is actually supported in Windows 7 ?

 

[Airbot]

I don't have a Pentium 4, I have a corei7, but hyperthreading works.

 

[darkassain]

yep i have it...

if you disabled it in the bios then it acts as one core as i remember it (and i believe it stays that way although you shouldn't quote me on that)....

just in case check if this is enabled...

 

[FTG]

Darn, looks like the feature is not enabled because I installed Windows 7 without turning it on in the BIOS. Oh well, will need to reinstall.

 

[7thangel]

when i had my p4, i didn't have to reinstall to turn on/off hyperthreading in my bios and neither should you. it's a simple change in your bios settings

 

[pillainp]

Control Panel>Device Manager: One or two CPU's listed? (If HT is on, the Device Manager should list two virtual CPU's under the Processor>Your Processor heading.

Task Manager>Performance Tab>View>CPU History>One Graph All CPU's or One Graph Per CPU selected?

 

[Digerati]

I agree with 7thangel. You should not have to reinstall - just enable it in the BIOS. But do make sure first you have TM set to display all as shown in darkassain's 2nd image.

 

[pillainp]

Would the "Number of CPU's" setting under the Boot>Advanced Options tab in MSConfig have any effect on this?

Would you check and see what it says? If it reads "1", set it to "2", reboot and see what happens.

 

[darkassain]

Would the "Number of CPU's" setting under the Boot>Advanced Options tab in MSConfig have any effect on this?

Would you check and see what it says? If it reads "1", set it to "2", reboot and see what happens.

it should in theory disable the virtual core..
and yeah i agree it should not take a reinstall for windows to enable HT

 

[Digerati]

You do not have two CPUs. You should leave it at 1.

 

[darkassain]

You do not have two CPUs. You should leave it at 1.

it depends since windows sees a P4 HT as "2" Logical processors but 1 core...
hold on ill test this right now...

edit just tried and yes it does disable the virtual core...
look at the pic
windows recognizes it as HT in the DM but deliberalty only uses one logical processor...

 

[Digerati]

Two processors means two CPUs in two sockets - such as you would find in a server board.

 

[MattRainier]

You do not have two CPUs. You should leave it at 1.

If it's a dual-core CPU, in the Search (Windows key) type in msconfig and go to Boot >> Advanced Options >> Number Of Processors. It'll probably be set to 1, so set it to 2 and reboot.

You can also enable the second core directly through the BIOS, though it varies from BIOS to BIOS.

 

[darkassain]

Two processors means two CPUs in two sockets - such as you would find in a server board.

yeah but it does not define physical processors since i just explained with pic on the edit above me...
it also applies to logical processors (i.e HT, multicore) too...

 

[pillainp]

A Hyperthreading CPU will be seen in DM, Task Manager and every other monitoring app (CPU-Z etc) as two virtual (logical) CPU's, since it uses two parallel execution threads.

Windows will treat it, for all intents and purposes as thought it were a dual core processor, not as if it were two discrete processors (dual socket).

 

[Digerati]

If it's a dual-core CPU, in the Search (Windows key) type in msconfig and go to Boot >> Advanced Options >> Number Of Processors. It'll probably be set to 1, so set it to 2 and reboot.

No. That is bad advice. That setting is for debugging purposes during the boot process only. It only affects the boot process so leave it at the default setting.

What is the motherboard make and model?

 

[FTG]

Well, I set HT to enabled in the bios, and re-installed. Still Windows shows 1 cpu graph. Then I went into bios and loaded all fields to defaults values, ( I don't know what else to try). And magically, Windows detects 2 logical cpus.

 

[Digerati]

There you go. Funny thing about defaults - they tend to work. Thanks for the follow-up.

 

[Slick1983]

I'd like to revive this thread. My Pentium 4 3.2 is showing a paltry 1.7 performance rating after installing Windows 7. The BIOS is set to hyperthreading. The boot shows "2" processors. The Task Master shows two and I've rerun the tests. What am I missing?

 

[logicearth]

What am I missing?

A modern processor. P4s are old, my Core 2 Duo at a measly 2 GHz outperforms a P4 clocked at 3+ GHz easily. Hyperthreading does not always equal better performance, btw.