At 11:32 AM 8/19/2004, you wrote:
>Your final quoted paragraph from Intel:
>
>"many applications are already multi-threaded and will automatically benefit
>from this technology"
>
>is EXACTLY what my 2nd point was - that applications don't HAVE to be
>written to support HT in order to benefit from HT.  Yes, if they are
>HT-aware they will perform even better - point given.  But your assertion
>that applications "must" (your word) be written to support HT - is WRONG.

No, I'm not wrong. What you are saying is that if you have a faster
processor then everything runs faster. You are taking the small boost, that
the operating system gains from HT, and then assigning it to the
performance of a particular application. If an application isn't coded to
take advantage of SMP and or HT, then the application will not directly
benefit from SMP or HT. The operating system may benefit, and run a little
faster, which causes things in general to run a little quicker, but that is
a different thing entirely, from a program, that supports SMP or HT.


>As for whether HT is will work with NT and 2000, I was going on second-hand
>information, from colleagues who have had problems because software that was
>licensed per-processor was seeing too many processors under Windows 2000.

Yes, there are licensing issues, above two processors, which is why
Microsoft states that Advanced server, that supports up to 8 processors,
offers some support for HT on Xeon systems. Windows servers get their
processor info from the BIOS, and if that is written to Intel specs, it
counts CPUs by using the first logical processor on each physical
processor. From Microsoft "Once Windows 2000  has counted a logical
processor on all of the physical processors, it will count the second
logical processor on each physical processor, and so on."If the BIOS is not
written correctly, Windows 2000, says MS, may use logical CPUs when it
should be using physical CPUs instead.The problem is that W2K doesn't make
a distinction between physical and logical processors on hyperthreading
systems, but just counts to the limit of licences using the first four CPUs
counted by the BIOS. Of course this is only going to be a problem on Xeon
systems.

But all this is incidental to the fact that the code is not within NT4, or
Windows 2000, to  fully take advantage of HT. Check any SMP or Dual
processor support group, and you will find that conventional wisdom says
that if you want to benefit from HT, then run XP PRO, and if you want to
run 2K then turn HT off.

Rode
The NOSPIN Group
http://freepctech.com


>At the moment I am building a 3.06GHz/533 P4 system for a friend and the HDD
>for that just arrived today, so I will verify whether 2000 reports 1 or 2
>processors and get back to you.  Of course I will make sure that I build-in
>the MP HAL - you may want take a look at whether your 2000 installation is
>using the UP or MP HAL.
>Carl

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