A note about my experience on using cusolver on sparse matrices.
I have implemented a wrapper around cusolver to solve sparse linear systems leveraging pytorch, and I need to say that I was disappointed with the performances for very large and very sparse matrices. Using the sparse linear solver from scipy lead to faster runtimes in my case.
I’m not sure about the performance for qr decomposition alone, but the solver of the linear system used qr factorization internally if I remember properly.