MATLAB freezes for a few minutes whenever I run a Fortran executable

I recently purchased a new computer and downloaded MATLAB R2016b. I use it often to plot results generated by Fortran code (separate from MATLAB, not as a mex file). However, whenever I run my Fortran executable, MATLAB freezes for several minutes. The program still responds, but it doesn't act on commands in the command line or run scripts for a few minutes. After a few minutes, it works as normal, but if I run my Fortran code again the same problem occurs. I've tried restarting MATLAB or running it as an administrator, but neither of these changes anything.

I used MATLAB in the same way on my old computer with no problems - I could plot results while my Fortran code was still running without any delay in MATLAB. Does anyone know why this is happening and/or what I could do to fix the problem? I'm using the Intel Fortran compiler on Windows 10, if that's relevant - my old computer was Windows 8.1 and it worked fine.

Answer 1

[James Tursa]

Sounds like the Fortran exe is using all of the CPU in your new setup, whereas it didn't before. E.g., maybe it didn't run multi-threaded before but now it is. Look at CPU usage to try and confirm this. Is this the same exe that you are running, or did you recompile it for your new computer?

[Samuel Goldberg]

This is what the CPU usage looks like while the code is running (middle ~50% of the image), so it does appear to be multithreading. However, the problem persists after my Fortran code is done running and CPU usage is back to normal, which doesn't make sense to me.

I did recompile it on my new computer, using the same compiler options as on my old computer.

[James Tursa]

" ...the problem persists after my Fortran code is done running and CPU usage is back to normal, which doesn't make sense to me. ..."

Hmmm ... me either ...