Re: Fiji - number of threads

Posted by Michael Schmid on Sep 14, 2013; 2:04pm
URL: http://imagej.273.s1.nabble.com/Fiji-number-of-threads-tp5004775p5004781.html

Hi Jiri,

at least for pure ImageJ (not FIJI, but I think there is no difference):
You have to restart ImageJ only if you have changed the amount of memory;
it should not ask you to restart if you only want to change the number of
threads.

In Prefs.java, line 374, the number of threads is written to IJ_Prefs.txt
only if it is >1.  I guess that the idea behind it is that setting it to 1
on multiprocessor machine is used for debug purposes only, and hardly
anyone wants to use only one processor on a multiprocessor system.
(Apart from debugging, as far as I can see, setting it to 1 may make sense
only if there is not enough memory for processing an image stack with
multithreading, which is quite rare).

What you can do:

In your Startup.txt file (ImageJ/macros), have a macro

macro "AutoRun" {
  run("Memory & Threads...", "parallel=1 keep run");
}

(delete 'keep' if you don't like the 'keep multiple undo buffers', e.g.
because you have large images and little memory).

Michael
__________________________________________________________________


On Fri, September 13, 2013 15:32, Jiří Borovec wrote:

> Good morning, may I have a question about the setting Memory & Threads. I
> changed the default nb of threads to 1, the it ask me to reset the the
> application. But after the reset then number of threads is always 4. What
> happened, the thread setting does not need restart or there is a bug that
> it does not change this parameter?
>
> Thanks, JB
> --
> Best regards and wishes of a nice day, Jiří Borovec
>

--
ImageJ mailing list: http://imagej.nih.gov/ij/list.html