Need to solve a large multiphysics problem on many GPUs in parallel? Just Relax!

JustRelax.jl is a Julia package for geodynamic modeling with matrix-free, accelerated pseudo-transient solvers. It supports two- and three-dimensional applications on CPUs and GPUs, including distributed-memory runs with MPI.

JustRelax.jl supports Julia 1.10 through 1.12. Start with the CPU backend, then use the backend guide to configure CUDA, AMDGPU, or MPI workflows.

The package is part of the PTSolvers organisation and was developed within the GPU4GEO project. For an overview of the methods and examples, see the documentation.

Highlights

• Matrix-free iterative solvers for Stokes, thermal, and coupled geodynamic problems.
• CPU and GPU backends, with support for CUDA and AMDGPU through Julia’s package extensions.
• MPI-based domain decomposition via ImplicitGlobalGrid.jl.
• Building blocks for material properties, particle methods, and constitutive…