- Algebraic Multigrid with Smoothed Aggregation (AMG)
- Approximate Inverse (AINV)
SpeedIT provides a set of accelerated solvers for sparse linear systems of equations. Thanks to our CMRS format SpeedIT is one the fastest technologies. The library runs with C/C++ and Fortran. It can also run with OpenFOAM to accelerate CFD simulations.
They also published short study “Acceleration of OpenFOAM with SpeedIT”:
OpenFOAM® simulations take a significant amount of time leading to higher costs of simulations. GPGPU technology has a potential to overcome this problem. As a solution of this problem we propose to use SpeedIT technology that replaces iterative solvers in OpenFOAM with their GPU-accelerated versions. In following tests we accelerate calculation of pressure equation that usually takes most of the time in simulations of incompressible flows. We compare the performance of OpenFOAM & SpeedIT run on GPU to standard OpenFOAM on CPU using various preconditioners on a typical PC equipped with NVIDIA GPU card that is CUDA compatible. This report is also used to present a new version of SpeedIT 2.1 that contains a new set of preconditioners.
To solve pressure equation with OpenFOAM on CPU either GAMG solver or CG with DIC preconditioner was used for different number of cores. On GPU SpeedIT was run together with AMG preconditioner. We have tested following test cases for fixed number of time steps.
- Cavity 3D 512K cells, icoFoam, on 1 and 2 Cores with PCG solver and DIC preconditioner, GAMG solver, FDIC preconditioner, Gauss-Seidel smoother, and SpeedIT 2.1 with AMG preconditioners.
- Aorta 200K cells, simpleFoam, on 1 and 2 Cores with PCG solver and DIC preconditioner, GAMG solver, FDIC preconditioner, Gauss-Seidel smoother, and SpeedIT 2.1 with AMG preconditioner.
- Ahmed case with 2.5M cells simulated with original simpleFoam, on 1, 2, 3 and 4 Cores with GAMG solver, Gauss-Seidel smoother and SpeedIT with AMG preconditioner.