How Windows 2000 Advanced Serve handle the Intel XEON MP Hyper Thrading

[Chan Yiu Hung]

I have read the article from Intel mentioned that the
operating system should implement two optimizations for
best performance.

From the article:
The first is to use the HALT instruction if one logical
processor is active and the other is not. HALT will allow
the processor to transition to either the ST0- or ST1-
mode. An operating system that does not use this
optimization would execute on the idle logical processor a
sequence of instructions that repeatedly checks for work
to do. This so-called "idle loop" can consume significant
execution resources that could otherwise be used to make
faster progress on the other active logical processor.

The second optimization is in scheduling software threads
to logical processors. In general, for best performance,
the operating system should schedule threads to logical
processors on different physical processors before
scheduling multiple threads to the same physical
processor. This optimization allows software threads to
use different physical execution resources when possible.

Did the optimizations already included on Windows 2000
Advanced Server?

[Andreas Bittner]

well i dont think so. hyperthreading in my opinion is really not a good
idea, if you really need computing power better get another real processor
and turn off hyperthreading support in the BIOS.

you might want to check some articles on performance issues.

Win2k was released 1999 and hyperthreading just showed up recently in the
latest Pentium4 cores.
so there is no real support or new code that supports hyperthreading. and i
guess intel will come up with some of their compilers with special
optimization for hyperthreading, but since win2000 isnt built specifically
for xeon hyperthreading architecture, just forget about it.

buy yourself some additional processors and dont use the hyperthreading in
the xeons.

check this page and the last paragraph for hyperthreading performance:
http://www6.tomshardware.com/cpu/02q1/0203131/dual-10.html

cheers,
Andy

"Chan Yiu Hung" <cha...@hk1.ibm.com> wrote in message
news:21f201c1dbb0$1a844e50$9ae62ecf@tkmsftngxa02...

[Jody L. Whitlock]

Out of personal experiance, Win2k AS has no issues that I've seen with
HyperThreading, it actually does run faster and cleaner. I have a new
server with Dual 2.2 Xeon P4's and it run's very smoothly. I run Exchange
SErver 2k and SQL Server 2K, and under heavy loads I've never seen either
proc spike above 40% usage. The only question I have about all this
HyperThreading on the new Xeon's is this: When the computer boot's, POST
shows 4 CPU's, although I only have two, and windows reads the two. I've
been told it's because BIOS traets each CPU as 2, has anyone else heard
this?
BTW, in reference to the CPU, I did nothing special to AS, I had to add the
/3GB switch cause I'm running 1024MB RAM. AS installed in 18 minutes, from
start to end, so I'm not thinking it has an issue with HyperThreading at
all.

HTH
Jody

"Chan Yiu Hung" <cha...@hk1.ibm.com> wrote in message
news:21f201c1dbb0$1a844e50$9ae62ecf@tkmsftngxa02...