Xeon Hyper Threading CPU's

[DMI]

I have read on Intel's site that hyperthreading should be
turned off in the bios when running W2K All versiions. Can
anyone confirm this to be true????

 

[Colon Terminus]

Both Microsoft and Intel recommend the same, yet users report different
results. The best sdvice is to try it both ways and choose whichever works
best for you. I have a machine that seems to yeild about a 5% performance
boost with HTT enabled. Your mileage may vary.

 

[Guest]

this is definitely not true I am currently running many
machines with w2k and hyperthreading is turned on

 

[Pavel A.]

I have read on Intel's site that hyperthreading should be
turned off in the bios when running W2K All versiions. Can
anyone confirm this to be true????

They advice so because win2k can't fully use capabilities of HT CPUs.
Performance boost is only about 5-10% - far below expected.
But power consumption and amount of heat is almost twice as when HT disabled -
without much performance gain. Machines with smart fans can become noisy...
If you're aware of all that, you can try and judge by yourself, whether HT works well on
your system with your apps.

Regards,
--PA

 

[Guest]

Microsoft neither confirms or denies that w2k supports hyperthreading. Assuming that you are talking about w2k server, they did publish a white paper that sort of explains how w2k handles logical processors. You can read it and make your own decision. http://www.microsoft.com/windows2000/docs/hyperthreading.doc

 

[Paul Hopwood]

I have read on Intel's site that hyperthreading should be
turned off in the bios when running W2K All versiions. Can
anyone confirm this to be true????

Windows 2000 is not optimised for HT CPUs but sees them as two logical
processors. It will work, but in most applications there is little or
no performance improvement.

--

 

[leanas]

A German IT magazine (ComputerBase.de) published an excellent articl
last summer about HyperThreading (HT)under Windows 2000 and Windows XP
They also included results of benchmarks with both operating systems.

The general gist of the article was that aside from all public remark
by Intel and Microsoft, HT DOES work under Windows 2000. Although th
Intel article says that HT is only supported in Windows XP Home an
Pro, the first Intel XEON processors with HT capability had worked wit
the Windows 2000 server, long before Windows XP was available!.

The document by Microsoft on this theme says only Windows XP support
IDENTIFICATION of logical processors; identification, not operation.
As Windows servers are licensed on the basis of the number o
processors running then it is to Microsofts advantage if people use th
XP server that can identify the number of real AND logical processor
in a system. So the lack of support from Microsoft for HT in Window
2000 may not be for purely technical.

That said, the results of the benchmarks that ComputerBase.de ra
wrere intersting in their own right. Many of the number crunching test
showed the same performance improvement with HT enables for both 200
and XP. Other tests showed a marked LOSS in performance with Window
2000 and HT enabled, for example WinRAR 3.11 Data compression progra
and Lame 3.91 Audio encoder: (the results are in minutes/seconds t
complete)

WinRAR 3.31
Windows XP 1.04
Windows XP/HT 1.04
Windows 2000 1:00
Windows 2000/HT 1.14

Lame 3.91
Windows XP 1.06
Windows XP/HT 1.06
Windows 2000 1:06
Windows 2000/HT 1.26

The article concludes that although Windows 2000 works fine withou
crashing, you should go for XP for more consistent performanc
improvement.

Recently at my company we tried an application of our own with H
enabled. This application used to run happily on dual Pentium II
processors under the Windows NT 4.0 multiprocessor kernel. Th
application makes extensive use of the multithreading capability. Th
test results with Windows 2000 and HT enabled were not ver
satisfactory. We would occasionally get a multithread lockup
Apparently even a gee-whiz 3.0Ghz Pentium IV can trip over its ow
feet now and again.

The article in question is at http://tinyurl.com/2abmv

It’s in German, but the benchmark results are understandable enough hi
the >> button at the bottom of the page to get to the following page.
(The real masochists can drop the article on Google or one of the othe
on-line translators

leana