Mathematica's CPU utilization

The Phantom

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Jul 30, 2005, 1:30:49 AM7/30/05

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After installing the latest 5.2 rev on my Pentium 4 running Windows XP, I thought to have
a look at the CPU utilization. While Mathematica was busy doing a long numerical
integration, and no other applications were running, I activated the task manager and was
surprised to see that the two main users of CPU time were the Mathematica kernel at 51%
and the system idle process at 48%. Does anybody know if it's possible to get the kernel
up to something closer to 100% utilization? Should I blame Mathematica or Windows XP?
wink, wink, nudge, nudge. ;-)

The Phantom

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Jul 31, 2005, 1:00:49 AM7/31/05

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Chris

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Jul 31, 2005, 1:31:34 AM7/31/05

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You probably have two or more processors or a dual core processor or a
processor with hyperthreading wink, wink, nudge, nudge.
Mathematica 5.2 does support using multicore processors, but only for
operations that can be performed in parallel, like dot product, etc. In
theory you could do numerical integration on two different processors
(just have it do two different parts) but I'm sure there are many
technical hurdiles in the way since Mathematica does a lot more than
just numerically integrate the function.

Wishmaster

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Jul 31, 2005, 1:32:24 AM7/31/05

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"The Phantom" <pha...@aol.com> escreveu na mensagem
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Are you using a Hyper-Threading Pentium IV CPU?

If so, I found that this seems to be normal: the same thing happens here.
100% load in 1 CPU and not much load in other.

[]s
--
[]s Renan (aka Wishmaster) - Canoas, RS, Brazil

my e-mail address is: renan DOT birck AT gmail DOT com
(nb: marreka.no-ip.com -> /dev/null)

Wishmaster

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Jul 31, 2005, 1:36:12 AM7/31/05

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"The Phantom" <pha...@aol.com> escreveu na mensagem
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Are you using a Hyper-Threading Pentium IV CPU?

Wishmaster

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Jul 31, 2005, 1:38:29 AM7/31/05

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"The Phantom" <pha...@aol.com> escreveu na mensagem
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Are you using a Hyper-Threading Pentium IV CPU?

Wishmaster

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Aug 1, 2005, 1:11:20 AM8/1/05

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"Chris" <top...@csh.rit.edu> escreveu na mensagem
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Maybe in the future, Mathematica will allow to run 2 kernels for the same
notebook - one using each "CPU"?

The Phantom

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Aug 2, 2005, 1:07:21 AM8/2/05

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On Sun, 31 Jul 2005 05:31:34 +0000 (UTC), "Chris" <top...@csh.rit.edu> wrote:

>You probably have two or more processors or a dual core processor or a
>processor with hyperthreading wink, wink, nudge, nudge.

It is a Pentium 4 with Hyperthreading technology (tm). Is that the same thing as a dual
core processor? I guess that would explain it.

Antti Penttilä

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Aug 4, 2005, 2:18:10 AM8/4/05

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The Phantom wrote:
> On Sun, 31 Jul 2005 05:31:34 +0000 (UTC), "Chris" <top...@csh.rit.edu> wrote:
>
>
>>You probably have two or more processors or a dual core processor or a
>>processor with hyperthreading wink, wink, nudge, nudge.
>
>
> It is a Pentium 4 with Hyperthreading technology (tm). Is that the same thing as a dual
> core processor? I guess that would explain it.
>

Hypertheading is not dual core, it just pretends to be dual core. That's why in Task Manager there is also two processors and graphs for them both. Mathkernel uses 100 % of the other (virtual) processor which is 50 % of the total capacity. Actually, since there is no real other core, Mathkernel uses all the CPU-time there is available. The CPU-usage numbers are a bit misleading with Hyperthreading processors.

--
Antti Penttilä Antti.I....@helsinki.fi.removethis