I have a PC with a P4 3.06ghz CPU and Windows XP Home edition. When I run the latest version of sisoft sandra it gives me a warning that my hyperthreading is disabled and needs to either be configured or the OS doesnt support HT processors.

Ive checked the BIOS and it is enabled and under hardware devices in windows it lists two cpu's so I'm not sure why I get this warning, can anyone help?

Also Ive always thought my PC isnt as fast as it should be with the hardware, could this be the problem?

Thanks.

P4 3.06ghz HT

1gb DDR RAM

120gb Samsung HD

GeForce4 Ti4600

Do you have 2 graphs in the task manager? If yes, the HT is enabled!

Well there is 2 graphs, one for cpu usage and one for page file. The cpu graph only has one green graph line going through.

OK, it sounds as if its disabled. If HT is enabled you should see 2 graphs for CPU and 1 for the page file.

SUMMARY

Both Windows XP Home Edition and Windows XP Professional treat a Hyper-Threading enabled computer as a multiple processor computer. You can verify this by looking in Device Manager, under the Computer and Processors nodes:

In Computer, you can expect the computer to be described as a multiprocessor PC.

In Processors, you can expect multiple processors to appear installed.

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.

but I found this also:

Even a Microsoft Corp. executive admitted he was wrong when he told eWEEK that Windows XP Home Edition would not support hyperthreading, based on the fact that only XP Pro supports multiprocessors.

"Windows XP Home Edition does in fact support hyperthreading," said Greg Sullivan, lead product manager for Microsoft Windows XP. "While Windows XP Home does not support multiple physical processors, it does support the multiple virtual or logical CPUs enabled by Intel's P4 and hyperthreading."

Altho people are saying that they show no major improvment in the home additiion compared to Pro version MS still says Home supports it. I can only assume that it may support it but does not utilize the hyperthreading like Pro version does.

The Task Manager with two CPU windows looks like this running PRO. Almost all Dual CPU motherboards already have Dual CPU support enabled in the BIOS by the manufacturer. If the BIOS was manually changed it would only support one CPU.

On a second note, I have never seen Home installed on a Dual CPU system.

The hyperthreading is definately disabled somewhere, have got just one graph. Can anyone suggest a fix or should I just install Pro?

The PC's performance is definately not as good as it should be.

In Task Manager ensure that it is set to show one graph per cpu under "View/CPU History". If not it will only show one graph for both even if HT is enabled.

It cant be selected, there is only one dimmed option that says "one graph per cpu".

How can I make sure hyperthreading is enabled? I want to squeeze the most juice out of my 3.2 GHz.

You can double check by going into your bios and enabling HT...It should say on startup that you have 2 cpus

Also in responce to prvius comments, dont expect double the performance out of HT, Hyper threading is a sythetic cpu that more effeciently deals with lost clock cycles..its not phyically 2 cpus in one nor will it perform like one...is mearlly a performance boot...somthing like 30% at bets.

=Drew

According to Intel, WinXP Home does support HT cpu's. Ive sent them an email about the issue and will post the reply here when recieved.

1st it needs to be enabled in the bios under your proc info. After that the OS should see it and treat it as 2 procs...I've not seen an option other than in the bios to enable/disable that feature.

This is what Intel said (not much use!):

Thank you for contacting Intel® Technical Support.

I understand your system only displays one processor in the Task Manager.

First I would recommend you use the Intel® Frequency ID Utility to properly identify your processor:

http://support.intel.com/support/processor...ls/frequencyid/

I would next suggest you contact Microsoft for any updates or patches that are available for the operating system to identify Hyper-Threading Technology:

http://www.microsoft.com/whdc/hwdev/platfo...HT-Windows.mspx

Please let me know if I can be of further assistance

Sincerely,

Naomi R.

Intel Technical Support

http://support.intel.com

I just installed XP Pro and I now get 2 processors in task manager. I think XP Home supports hyperthreading CPU's but doesnt take advantage of it like XP Pro with dual processor support.

With hyperthreading you will see 2 CPU's. My mate has it (3.06 GHz) and he see's 2 CPU's and this is correct.

If this has already been said sry, i just woke up... lol.