Sign in with
Sign up | Sign in
Your question

Windows Dual Core Hotfix for Hyperthreading?

Last response: in CPUs
Share
December 12, 2006 10:20:20 PM

I read a minute ago in an MobilityGuru article on an Alienware laptop that the guy installed a Hotfix from microsoft that enabled dual core in XP?

http://www.mobilityguru.com/2006/12/12/alienware-area51...

"I did a little digging, and found a hotfix from Microsoft that enables dual core support in Windows XP. I installed it and ran 3DMark05 again. I got a new score of 3201. "

Would this work with my Pentium 4 Prescott 3.2ghz Pentium 4 540 with Hyperthreading. If all it does is make XP multithreaded, then it should increase performance when using Hyperthreading.

Where can I get this?
December 13, 2006 12:58:40 AM

Dose it really work?

I want multithreaded XP and what hotfix?
Related resources
December 13, 2006 1:40:43 AM

Oh....that patch - I was trying to figure out what he was talking about....

Applied it awhile back - did nothing for my machine....performance is exactly the same...
December 13, 2006 1:41:24 AM

Yeah, I found that on Google (was going to link it myself), but it specifically says "computers...equipped with multiple processors." You could contact Microsoft to be sure (good luck) but I doubt it applies to Pentium 4s that hyperthread, it's still one physical processor, with one physical core. Worth a try though.
a b à CPUs
December 13, 2006 2:11:10 AM

That hotfix reffers to the timestamp synchronisation of the processors, or cores on a multi-CPU or multi-core PC. Some programs-games get confused when trying to divide the work between the two cores and the result is degraded performance. What this hotfix does is help the two cores synchronise the division of work between them, in such a way as to not introduce a lag in the system. If i remember well Call of Duty 2 and Quake 4 had this issue. After the hotfix, all lags should be gone.
As always, before applying the patch make sure to create a restore point.
December 13, 2006 2:35:45 AM

Yes, but it's one physical core in the case of the Pentium 4s, like I said. I'm still not sure, since Windows does see two logical cores, but it doesn't seem to me like a program would have a problem splitting the load because there is one core. It's so confusing I'm starting to get redundant. :wink:
a b à CPUs
December 13, 2006 2:43:19 AM

Quote:
Yes, but it's one physical core in the case of the Pentium 4s, like I said. I'm still not sure, since Windows does see two logical cores, but it doesn't seem to me like a program would have a problem splitting the load because there is one core. It's so confusing I'm starting to get redundant. :wink:


I think you are confusing Hyperthreading (HT) with the actual two core existense. In the case of HT windows cannot tell the difference between two virtual cores or two actual cores. And therefore will try to balance in exact the same way as if you had an actual dual core CPU. Hence you will experience the same kind of behaviour. Now the results could be different because of the way of the implementation of HT in the CPU.
December 13, 2006 1:39:00 PM

Hyperthreading is more inefficient than actually having two cores, either with two dies or one die. And as a general notice, some PC come with it preinstalled, some don't. Some people don't experience the problem, others do.
a b à CPUs
December 13, 2006 8:49:39 PM

Quote:
Hyperthreading is more inefficient than actually having two cores, either with two dies or one die. And as a general notice, some PC come with it preinstalled, some don't. Some people don't experience the problem, others do.


Me saying that i strongly disagree... that would do nothing. The fact that Intel REMOVED HT from their processors should tell you something. And if you still don't get it, then drop them an email and tell us the answer.
December 14, 2006 12:17:08 AM

Can you read man? I said inefficient. You quoted it.
a b à CPUs
December 14, 2006 12:20:00 AM

Quote:
Can you read man? I said inefficient. You quoted it.


LOL! /me bows!
My apologies monsier! My eyes work faster than my brain!
By the way, HT is not installed or not installed, it is either supported by both the CPU and the BIOS and ENABLED or not by either and DISABLED.
I believe i read that right.

:) 
December 14, 2006 12:23:15 AM

Yep, you got that one right. Its a hardware issue, just like Speedfan.
December 14, 2006 12:28:13 AM

Sh*t, I meant Speedstep not Speedfan. :oops: 
December 14, 2006 12:43:15 AM

If you're running SP2 you don't need the hotfix, it's included. This is at the bottom of the Microsoft hotfix page:

"MORE INFORMATION
Windows XP SP2 is required on computers that have multiple CPUs that support ACPI processor performance states. This requirement includes computers that support the following items:
• Multiple physical sockets
• Multiple-core designs
• Multiple logical threads, such as Intel hyper-threading technology
Because Windows XP was not originally designed to support performance states on multiprocessor configurations, changes are required to correctly realize this support on multiprocessor systems. Windows XP Service Pack 2 includes the required changes to the kernel power manager. These changes make sure that Windows XP correctly functions on multiprocessor systems with processor performance states."
a b à CPUs
December 14, 2006 1:37:45 AM

Quote:
If you're running SP2 you don't need the hotfix, it's included. This is at the bottom of the Microsoft hotfix page:

"MORE INFORMATION
Windows XP SP2 is required on computers that have multiple CPUs that support ACPI processor performance states. This requirement includes computers that support the following items:
• Multiple physical sockets
• Multiple-core designs
• Multiple logical threads, such as Intel hyper-threading technology
Because Windows XP was not originally designed to support performance states on multiprocessor configurations, changes are required to correctly realize this support on multiprocessor systems. Windows XP Service Pack 2 includes the required changes to the kernel power manager. These changes make sure that Windows XP correctly functions on multiprocessor systems with processor performance states."


I believe you are talking about something else...

http://support.microsoft.com/kb/896256

It clearly states that its for WinXP with SP2.
a b à CPUs
December 14, 2006 2:24:26 AM

I believe you read it wrong: First of all the title of that page:

"Computers that are running Windows XP Service Pack 2 and that are equipped with multiple processors that support processor power management features may experience decreased performance"

Then later:

"APPLIES TO
• Microsoft Windows Server 2003, Standard x64 Edition
• Microsoft Windows Server 2003, Enterprise x64 Edition
• Microsoft Windows XP Service Pack 2, when used with:
Microsoft Windows XP Home Edition
Microsoft Windows XP Professional

• Microsoft Windows XP Tablet PC Edition 2005

Back to the top
"

Always read the : APPLIES TO section to make sure which version of windows is related to that topic.

:) 
December 14, 2006 2:42:55 AM

For several months I used my PC with HT turned off. An example of HT's power is: playing HD 720p Quicktime H.264 without HT taxes my CPU at 70 percent. WITH HT, it only uses 45 percent. This is because Quicktime is a multithreaded app.

I notice huge performance differences while using HT. So dont dis HT if you havent used it.

No one has come out with a final decision whether or not my HT enabled CPU can utilize this phantom hotfix. Not exactly sure what you all are talking about, just that you havent come to a conclusion.
December 14, 2006 3:27:13 AM

Quote:
For several months I used my PC with HT turned off. An example of HT's power is: playing HD 720p Quicktime H.264 without HT taxes my CPU at 70 percent. WITH HT, it only uses 45 percent. This is because Quicktime is a multithreaded app.

I notice huge performance differences while using HT. So dont dis HT if you havent used it.

No one has come out with a final decision whether or not my HT enabled CPU can utilize this phantom hotfix. Not exactly sure what you all are talking about, just that you havent come to a conclusion.


No.... its because of how hyperthreading works. For example, a single threaded app on a core2Duo is capped at 50% CPU usuage (100% of one core) a multi-threaded app is capped at 100% CPU usuage (100% of 2 cores). Similarly running at 50% utilization is 100% of a "virtual core". YOu cannot compare the 70% usuage without HT to the 45% with HT just by comparing the numbers. With HT you may see more reponsiveness, but it is mainly due to the fact P4's have very long pipelines which results in many lsot instructions... without HT on the P4 you end up with more NoOps. However, HT in itself isn't a good thing (or a bad thing) its merely a solution to a problem with that specific design.
a b à CPUs
December 14, 2006 10:37:15 PM

Quote:
For several months I used my PC with HT turned off. An example of HT's power is: playing HD 720p Quicktime H.264 without HT taxes my CPU at 70 percent. WITH HT, it only uses 45 percent. This is because Quicktime is a multithreaded app.

I notice huge performance differences while using HT. So dont dis HT if you havent used it.

No one has come out with a final decision whether or not my HT enabled CPU can utilize this phantom hotfix. Not exactly sure what you all are talking about, just that you havent come to a conclusion.


Read the response below...
On top of that, it is obvious that you do not understand the fundamental differences between P4's HT and a true dual core system. I did not say that HT was a total disaster, but due to its nature it created a lot of problems as many as it solved. Maybe with your software you didn't come across any (lucky you), but do a google and you will find hundreds if not thousands of programs with incompatibilities and problems. If it works for you then good, keep on using it. But you can't tell the CAD designer that he can't even launch AutoCAD to do his work with HT enabled that its a boon!
!