Using CUDA for (or to replace) Successive over-relaxation solver

I am working on a 1980s Fortran modeling groundwater and heat flow for geothermal application. It solves linear equations re. pressure and heat flow. It has a dedicated solvers which is fully programmed in Fortran (ie. no use of any library). Would anybody have some information whether CUDA would make a good replacement of this solver and how to approach an implementation. Thx jcherw

Have a look at the cuBLAS documentation and see if it has the features needed for your current implementation.
Though I have used BLAS Fortran for solving linear equations, I have never tried cuBLAS myself yet, so I can’t comment further.
But most likely the answer is yes.

You can start here
https://www.pgroup.com/resources/docs/19.3/x86/cuda-fortran-prog-guide/index.htm#cfref-fort-mods-host-mods

You may want to take a look at the CUSP library https://cusplibrary.github.io/. It supports several solvers, if you can write your operators as sparse matrices.