Pentium 4 Hyperthreading

[Mr Digital]

Hi all,

Any users of this technology find it any better??

I have just upgraded from an AMD Athlon 2600xp to a P4 3.2Ghz with a 1024kb
L2 cache & 800Mhz fsb.

It's true what they say about hyperthreading that it fools your pc into
thinking it has 2 CPU's.

Phil.

 

[WebWalker]

It's true what they say about hyperthreading that it fools your pc into
thinking it has 2 CPU's.

Yes, it is.
Check the "Task Manager"'s Perfomance tab.

 

[HankG]

Yes, it is.
Check the "Task Manager"'s Perfomance tab.

I have a P4, 3.07 Ghz w/1 GB RAM (and HT). I opened Task Manager. then
with Outlook Express and IE open, I clicked on a couple of programs. The
CPU usage fluctuated up and down, peaking at about 40%. The Page File usage
also increased.

Prior to getting this (an H-P) computer, I purchased an H-P Media Center
comp. w/ P4 2.8 Ghz and 512 MB RAM. It had a 160 GB 7200 RPM HDD (don't
remember cache details) and HT vs. my current 5400 RPM 250 GB HDD. The
first computer developed an extreme overheating problem and had to be
returned--there were no more (exact) to replace it.

By comparison, the first computer was faster opening programs, connecting
and downloading from the Internet, etc. From what I have read and have been
led to believe, HDD performance makes more difference in overall system
performance.

Is there something on Task Manager that I'm missing?

HankG

 

[Joe Morris]

Any users of this technology find it any better??

Depends on your application, and the application mix. My shop has run
some rough benchmarks and found that in *some* environments we can see
a 40% performance drop when HT is disabled; in others the difference
is trivial. As usual, YMMV.

Amusing anecdote: last spring we were evaluating a small-form-factor
system (prior to its official announcement); the box had a Prescott
CPU with HT capability. For a raw speed test we run SETI At Home;
everything was fine. We then started a second SETI At Home thread
to exercise the HT feature; it worked, but the additional load on
the CPU caused it to heat up, causing the CPU fan to speed up to the
point that its noise was unacceptable in an office environment. For
this (and other reasons) we rejected the box.

Joe Morris

 

[Curious George]

Is there something on Task Manager that I'm missing?

HT must be enabled in the BIOS and you must be using a multiprocessor
hal for both logical cpu's to show in the task manager.

The benefit of HT is basically smarter resource allocation for
multitasking. Just like with a true SMP machine no one CPU intensive
app will monopolize resources so there is additional headroom (the
system doesn't seem to slow up) even when a running process hammers
the cpu.

There isn't as much raw horsepowers with HT compared to a true dual
cpu system and there is a slight performance penalty in many apps when
HT is enabled. IMHO it's very worthwhile for general, moderately
intense multitasking but not for specialized tasks (per drawbacks
mentioned above).

 

[Curious George]

Amusing anecdote: last spring we were evaluating a small-form-factor
system (prior to its official announcement); the box had a Prescott
CPU with HT capability. For a raw speed test we run SETI At Home;
everything was fine. We then started a second SETI At Home thread
to exercise the HT feature; it worked, but the additional load on
the CPU caused it to heat up, causing the CPU fan to speed up to the
point that its noise was unacceptable in an office environment. For
this (and other reasons) we rejected the box.

Joe Morris

SFF, Prescott, Full load - usually not a great mix. Most sff chassis
don't deliver enough cool outside air to meet prescott integration
guidelines - or they have that silly ducting which is just asking for
trouble with many employees & work environments.

 

[Mr Digital]

Thanks everyone for your comments.
One of you mentioned that it will only function if enabled in bios of which
it is.
If i run DXDIAG, in the CPU description it is saying that there are 2 CPU's.

Phil.