I’d like to make use of fenics’ built-in parallel functionality. I’m using a MacBook Pro with anaconda, but other machines are available if needed. If I run the Cahn-Hilliard example it seems to use all cores with the standard solver lu. This takes around 35 s on my machine.
If I change to gmres it takes 10 s and doesn’t seem to use more than one core. How do I make it use all cores with gmres?
The mesh in my real code is substantially larger and cannot practically use lu, hence my question how to paralllelize other solvers.