HT CPU on WinXP Pro

[TheDuck Man]

I've got a new computer.
It is based on an Intel RockLake m.b. (865 chipset) HT
Processor 2.4Ghz with an 800Mhz bus and (for now, but not
for long) 256MB of DDR400 (which will be upgraded to 1GB
soon).
A fresh copy of Windows XP Pro was installed on the new
hardware. SP1a and all critical updates installed, as
well...
It runs like a dream, but I have some hangs from time to
time, when running many applications at once.
This shouldn't happen on an HT CPU machine that acts as a
Dual Processor. The load SHOULD be balanced.

The questions are:
1. Does Windows XP works right with Dual CPUs *Out Of The
Box*, or should I do something with it to enable the OS to
work with both processors?
2. Does Windows XP knows how to balance applications EVEN
THOUGH THEY WERE NOT COMPILED TO WORK WITH DUAL CPUs, so
that they will not engage one CPU all the time?
3. Did Microsoft ever developed a kind of a patch to
create some kind of load balancing of legacy applications
(the kind that does NOT function properly on Dual
Processor machines)?

Any help will be appreciated.
Answers to my mailbox will be even better )

TIA

TheDuck Man

 

[Guest]

also, hyperthreading is a far cry from having 2 cpus.

what hyperthreading essentially does is enables the cpu to
execute more threads than it normally does by shoving more
threads into the pipeline; the single cpu uses more of its
capacity...it is seen as a second VIRTUAL cpu. It IS NOT
the same as 2 cpus...but CAN be better than one.

 

[David Hollway]

I've got a new computer.
It is based on an Intel RockLake m.b. (865 chipset) HT

A good motherboard - I have one myself!

It runs like a dream, but I have some hangs from time to
time, when running many applications at once.

A "hang" is not a symptom of HT not working properly. If the machine truly
"hangs" - i.e, locks up and requires a reboot - then I suggest you have a
hardware fault somewhere. Check the following:

1) is the memory good quality, preferably from the tested list at:
http://support.intel.com/design/motherbd/rl/rl_mem.htm ?
Beware the "low latency" stuff targetted at enthusiasts - shiny
heat-spreaders (unnecessary on DDR) and a "kool" name are not a substitute
for quality! I personally always use Crucial / Micron RAM (www.crucial.com)
and have never had a problem with it.

2) heatsink & fan installed properly? Install the Intel Active Monitor
utility and check your temperatures, fan speeds and voltages are all within
margin. IAM is included on the CD with the motherboard, or can be downloaded
from:
http://www.intel.com/design/motherbd/active.htm

3) Checked for viruses?

This shouldn't happen on an HT CPU machine that acts as a

As I said above, TRUE "hangs" - where the machine locks up - shouldn't
happen on ANY machine. HT has nothing to do with it.

Dual Processor. The load SHOULD be balanced.

The questions are:
1. Does Windows XP works right with Dual CPUs *Out Of The
Box*, or should I do something with it to enable the OS to
work with both processors?

If you are using Service Pack 1, then HT will be auto-detected when you
enable it in the BIOS and the appropriate DP kernel will be loaded. To check
that HT is enabled, bring up the Task Manager (right-click on the taskbar,
and select "Task Manager") then click the "Performance" tab. If you are
using HT, then you'll see two separate "CPU Usage History" graphs.
You must also install the Intel Chipset Update, preferably BEFORE you
install any other drivers, i.e right after the OS install. The ICU is on the
CD with your board, or from
http://support.intel.com/design/motherbd/rl/rl_drive.htm

2. Does Windows XP knows how to balance applications EVEN
THOUGH THEY WERE NOT COMPILED TO WORK WITH DUAL CPUs, so
that they will not engage one CPU all the time?

It'll do its best to balance the total number of applications running on
each processor, but a single application will only use both processors if it
is multi-threaded. The behaviour of XP in this regard is the same on an HT
processor as on a "real" dual-processor system.

3. Did Microsoft ever developed a kind of a patch to
create some kind of load balancing of legacy applications
(the kind that does NOT function properly on Dual
Processor machines)?

Not that I'm aware of, but there shouldn't be a problem - the app will run
on one "processor", leaving the other "processor" for the kernel tasks.

Any help will be appreciated.
Answers to my mailbox will be even better )

I can't mail at the moment, but if you see this response in the NG, please
post a reply - I don't think my news server is working at the moment, as
none of my recent posts have ever appeared on the newsgroup.

TheDuck Man

Duck Man as in, "Buggrem, millennium hand and shrimp"?

 

[Guest]

Dear David Hollway,
Thank you *very much* for the ingight!
My system doesn't realy hangs, as in "Hang" it just stalls
for a brief moment from time to time. As if the CPU is too
busy...
My memory chips are Kingston originals. I got the whole
package from friends working in Intel, so they only have
compatible parts...
I have checked, and sure enough I have two CPU Usage
History windows. Thank you.
Another LITTLE question I have is: Was the new Office 2003
(or the Office System) written & compiled to work on an HT
systems as on a dual CPU systems?

Have a good one.
TheDuck Man

(TheDuck as in "The Rubber Duck" from the
movie "Convoy"... Friends say I look like Kris
Kristofferson and I liked the character in the movie.
Besides, who wouldn't like Eli McGraw??? )) )

 

[Guest]

Dear David Hollway,
Thank you *very much* for the ingight!
My system doesn't realy hangs, as in "Hang" it just stalls
for a brief moment from time to time. As if the CPU is too
busy...
My memory chips are Kingston originals. I got the whole
package from friends working in Intel, so they only have
compatible parts...
I have checked, and sure enough I have two CPU Usage
History windows. Thank you.
Another LITTLE question I have is: Was the new Office 2003
(or the Office System) written & compiled to work on an HT
systems as on a dual CPU systems?

Have a good one.
TheDuck Man

(TheDuck as in "The Rubber Duck" from the
movie "Convoy"... Friends say I look like Kris
Kristofferson and I liked the character in the movie.
Besides, who wouldn't like Eli McGraw??? )) )

 

[Guest]

I stand corrected and thank you for the insight!

 

[David Hollway]

I stand corrected and thank you for the insight!

To add to the earlier explanation.. what HT basically does is maximise use
of the processor's resources.
Here's a simplified example. Say that you have two tasks running - one is a
program that performs integer operations only (e.g an MP3 encoder) and the
second is a task that uses mainly floating-point maths (e.g a 3D renderer).
With a non-HT single processor system, the OS kernel schedules the two tasks
alternately, switching rapidly between them. This is "simulated"
multitasking - the CPU is only doing one task at a time, but it appears to
the user to be doing two things at once because it's swapping so quickly
between them.
In each successive slice of time, the processor executes Task 1 (meaning
that the processor's integer units are in use, but the Floating point unit
is idle), then Task 2 (integer units are idle, FP unit is in use), then task
1 again, then task 2 again, etc etc etc.. this gets the tasks done, but
quite inefficiently, because half the processor's resources are idle at any
one time.

With an HT system, on the other hand, the OS kernel sees two "processors"
and schedules the two tasks accordingly, combining the elements of the tasks
where possible. To an extent, this is "true" multitasking - the CPU really
is doing two tasks at a time.
In each successive slice of time, the integer units of the processor are
executing Task 1 and the Floating point unit is executing Task 2... This
gets the tasks done far more efficiently, because all the processor's
resources are utilised continuously.

As I said earlier, that's a gross oversimplification - in real life, you're
unlikely to have two tasks that so neatly combine together (e.g one task
might use the integer unit but also need some FP operations), plus there's
all the other tasks (OS, background programs, etc etc), but I hope the above
example at least shows the principle behind Hyper-Threading technology.

It doesn't have to be two seperate applications, as in my example; it can be
two tasks within THE SAME application. In this case, the application tasks
are called "threads". For example, in a game, one "thread" might be
calculating the position of the player, the enemies, the bullets etc, while
another "thread" might be calculating the position of the scenery and
sending it to the graphics card for rendering. Such applications are
referred to as "multi-threaded".

In short, HT offers a performance advantage for both multiple,
single-threaded apps, and also for multi-threaded apps. The exact amount of
performance increase varies; for some (combinations of) apps it is minimal
or zero, whereas for others (e.g Maxon Cinema 4D, Windows Media Encoder,
etc) it can be up to 30% or more.

BTW, don't post using your (presumably) real e-mail address - spammers trawl
newsgroups looking for addresses to add to their lists and you'll find
yourself getting even more spam.

Hope this helps,

-David Hollway [MVP]