How does Underworld scale on a HPC? In this post we showcase how Underworld 2.11 scales across two of Australia's premiere HPC systems. Gadi - https://nci.org.au/our-systems/hpc-systems Magnus - https://pawsey.org.au/systems/magnus/ The reference model chosen for this scaling showcase is a extended 3D stokes flow: Analytic Solution SolDB3D . Q1P0 elements were used and a fixed solver iteration count for solving the saddle point problem.