Hi,
I am rendering a number of images on a machine with multiple processors.
I'm using rpiece with the -PP option (splitting into 4 pieces with the hope
of running one on each or the 4 processors in my machine), but still only
ever seem to be using 1 processor at a time.
I get multiple rpict threads, but only one of them seems to do anything at
any one time.
Does anyone know where I'm going wrong, or even if it's possible to use
multiple cpus in the same machine at once?
Many thanks,
Glen Harding.
Glen Harding
Bradford School of Optometry and Vision Sciences
University of Bradford
BD7 1DP
Tel: 07969 797391
Hi Glen!
I am rendering a number of images on a machine with multiple processors.
(...)
Does anyone know where I’m going wrong, or even if it’s possible to
use multiple cpus in the same machine at once?
It is possible, and asked here from time to time. The trick is to start
one with all the command line arguments and the others without, so that
they will take over from the parent process. BUT: If you have several
frames to render, I would not care. It is much easier to render the
frames in parallel then slicing the single images. And to render all the
views at one (if you have enough processors) you just call rad -N 8 (for
eight CPUs), and it will start eight images at once for you. Much
easier, same effect.
Besides that, if you have really lots of frames, I have an old
documentation on how to use ranimate for similar stuff:
CU Lars.
Hi Glen,
The -PP is used for memory sharing on a single host running multiple processes. If you have a machine with 4 cores then you will need to start 4 copies of rpiece. So with something like the following:
rpiece -x 800 -y 800 -X 2 -Y 2 -F my_syncfile.sync <rpict options
including -PP my_persistfile.pp> -o myimage.unf myscene.oct
this command line would need to be run 4 times in order to get the 4
processes up and running
This would result in an image split into a 2 by 2 grid and spread out over 4 processes. The memory including the scene would be shared among the 4 processes, thus reducing the memory footprint.
This can be automated simply using a Makefile or with other tools such as Perl or Python.
Let me know if you have any further questions and I can try to answer.
-Jack de Valpine
G HARDING wrote:
···
Hi,
I am rendering a number of images on a machine with multiple processors.
I’m using rpiece with the –PP option (splitting into 4 pieces with the hope of running one on each or the 4 processors in my machine), but still only ever seem to be using 1 processor at a time.
I get multiple rpict threads, but only one of them seems to do anything at any one time.
Does anyone know where I’m going wrong, or even if it’s possible to use multiple cpus in the same machine at once?
Many thanks,
Glen Harding.
Glen Harding
Bradford School of Optometry and Vision Sciences
University of Bradford
BD7 1DP
Tel: 07969 797391
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