please find attached a graph illustrating the speedup with PaStiX for 9 representative examples (ranging from 700,000 to 5,000,000 degrees of freedom) involving face-to-face penalty nonlinear contact calculations. The graph is taken from the Master Thesis of Peter Wauligmann, who implemented the interface with PaStiX. The default implementation in CalculiX is “mixed”, which means first a direct solve in single precision followed by an iterative refinement in double precision. “GPU” means the installation of all packages described in the README-file, i.e. Cuda, Parsec, hwloc, scotch and PaStiX.
I do not think Peter Wauligmann has uploaded his thesis yet, however, in the past he allowed me to send his thesis to whoever is interested. So just send a mail to firstname.lastname@example.org and I will send you the pdf version.