limit number of threads used by Paraview



I am currently trying out Paraview 5.6.0 (with OpenGL and OSPRay 1.7.3 support) on a machine sharing ressources with multiple users - client/server on the same machine.
I could limit the number of thread used by OSPRay rendering using OSPRAY_THREADS environment variable however I do not know if it is possible to do the same with Paraview itself (or VTK) - to get more control over resource usage.