From: John Stone (
Date: Thu Sep 05 2013 - 09:43:18 CDT

See the other email I just sent regarding using "-numthreads".
Also, if you add a "+V" to the rendering command, Tachyon
will report how many CPUs it sees and is actually using.
When you're watching the CPU load, you will want to make sure that:
  1) You're watching the CPU load while Tachyon is actually in the
     rendering stage and not in the process of reading files or
     doing preprocessing, both of which only use 1 CPU. Only the rendering
     stage uses all of the CPUs.

  2) Your machine isn't running out of memory (paging will cause
     very low CPU utilization because the CPUs get bogged down waiting
     for the hard drive)..

  John Stone

On Thu, Sep 05, 2013 at 11:02:10AM +0200, Albert wrote:
> On 09/05/2013 08:01 AM, Norman Geist wrote:
> >Hi Albert,
> >
> >how do you know that? As far as I know tachyon uses a shared memory
> >parallelism, therefore you will usually find _one_ process only, what
> >doesn't mean, it uses only one core. Check the amount of cpu usage
> >percentage the process has, you might notice some 100%.
> >
> >Norman Geist.
> that's very easy to monitor this. I checked the usage of CPU by htop
> command. I only see very small amount of percentage was used...
> Albert
> >
> >>-----Ursprüngliche Nachricht-----
> >>Von: [] Im
> >>Auftrag von Albert
> >>Gesendet: Mittwoch, 4. September 2013 10:05
> >>An: vmd maillist
> >>Betreff: vmd-l: how to enable multiple core rendering?
> >>
> >>Hello:
> >>
> >> I am using the tachyon engine for rendering in VMD-1.9.1 and I notice
> >>that only one core of my CPU was used for job. I am just wondering how
> >>can we enable multiple core for the rendering course?
> >>
> >>thank you very much
> >>Albert

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