HyperThreading, how can I install Windows 2000 and use it?

[IsOs]

Has anyone successfully used HyperThreading with Windows 2000? Could you please state the manner that you installed Windows 2000?

I know that using Windows XP Pro is the preferred way. But Windows XP disabled my NetBEUI Lan when SP1 was installed.

Any help is appreciated.

 

[galt]

I dont think w2k supports hyperthreading. Hell, my w2k sp4 cd wont even support 48bit lba, which microsoft *says* it does.

 

[spyordie007]

Win 2K doesnt "support" HT however if it is a single CPU box you can install on it and Windows will think that it is 2 CPUs.

The other option would be to disable HT in the bios (this is the MS/Intel support/reccomended/suggested way).

-Spy

 

[kylef]

HyperThreading on Win2k is not supported because Win2k detects your single HT cpu as two CPUs. The reason this is BAD is that the system idle process, which is implemented as a NOOP in Win2k, will steal CPU cycles away from other running programs. This happens because a NOOP instruction competes with regular integer instructions on a HT cpu for the same resources. If you truly had two CPUs, this would not happen.

So I would recommend that you disable hyperthreading to achieve best performance in Win2k.

WinXP, on the other hand, recognizes the HT cpu and behaves accordingly.

Don't know if MS can fix this for Win2k... it would involve changing the kernel itself, which might affect regular system behavior and introduce problems into "legacy" systems. Microsoft is traditionally afraid to implement big changes like this because such changes tend to break the existing configurations...

 

[SearchMaster]

Interesting.

I have HT enabled on my Win2K Server box. I have noticed a dramatic increase in responsiveness for extremely CPU-intensive processes, and for that reason alone I will probably keep it enabled. Otherwise, I can't see any differences.

 

[kylef]

Here's a link that describes part of the problem, in case you're interested:

Microsoft's HT Support Statement

It could be that Win2k server has some HT support, I don't know. But Win2k Workstation definitely does not. There are some circumstances in which HT can speed up even a Win2k workstation computer (e.g., when a floating point app and integer app are running simultaneously), but single-application performance (with no other load-intensive thread running) is typically worse due to the spin-lock NOOP contention from the "2nd cpu" idle thread.

 

[IsOs]

Thanks for the information. I'm currently running this system in Windows 2000 Pro with HT enabled. I'll play around with this a little.

I don't think I'll have a problem with the System Idle. Running SETI with SETI Driver defaulting to 2 processes doesn't event give any time for System Idle during the first 6 hours of operations.

 

[spyordie007]

I think the biggest performance problems come when running Windows 2000 (any version) on a box with multiple HT CPUs. Say you have Windows 2000 Server on a dual HT CPU system, Windows will think it has 4 physical CPUs and when running 2 threads can end up running the 2 threads on the first physical CPU (logical CPUs 1 and 2) while leaving the second physical CPU (logical CPUs 3 and 4) idle.

There's also the problem with the system idle process as mentioned earlier.

-Spy

 

[jswjimmy]

i think 2000 pro will work but i would go with xp pro

 

[Shimmishim]

i have ht disabled with 2000 pro

if you try benching things, it will only use 50% of the cpu or 1 of the 2 processors that 2000 recognizes...

saw my pcmark2k2 score go from 6400 to 8600 after disabling HT