I'm doing a PhD in physics using using large scale numerical codes. From what I can see more computer-science would mainly improve the maintainability rather th

I'm doing a PhD in physics using using large scale numerical codes. From what I can see more computer-science would mainly improve the maintainability rather than the speed of codes used. They are often already heavily optimized and, for the numerical heavy lifting rely on standard libraries such as Intel's MKL. Also scalability is usually quite good since the codes are routinely developed to run on a large number of CPUs in parallel. GPU support is coming slowly since it's also new to the people who developed Fortran codes for the last 20 years. For example VASP, a popular atomic structure simulation, is getting GPU support just now through a public-private partnership with nVidia. The speed-up for a 16-core sandy-bride machine with and without two GPU cards is about up to factor 8.