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Re: maximum number of threads limitation?

Posted by Rasband, Wayne (NIH/NIMH) [E] on May 15, 2014; 4:40pm
URL: http://imagej.273.s1.nabble.com/maximum-number-of-threads-limitation-tp5007744p5007753.html

On May 15, 2014, at 2:55 AM, Messaoudi Cedric wrote:

> Hi,
>
> I have a computer with 40 cores with HT (so maximum number of threads is 80).
> With ImageJ, I changed the parallel threads property via Edit>Memory and threads, I could give any number so in my case 80 (instead of the default 32)
>
> But when I checked again the value, it was reduced to 32 threads. It seems I can't allocate more than 32 threads.

The 32 thread limitation is removed in ImageJ 1.49a.

-wayne

> I looked at source code and found that this limitation is present in the class Prefs method setThreads(int n)
> Where I found this instruction
> if (n>32) n = 32;
>
> so there is a hard-coded limitation to 32 threads.
>
> Is there any (good) reason for this limitation to 32 threads?
>
> Best regards,
> Cédric
>
> ----------------------------------------------------------
> Cédric MESSAOUDI
> Institut Curie - INSERM U759 Laboratoire d'Imagerie Intégrative
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