I've only just joined the petsc-dev list, but I'm hoping with this subject line my email will join the right thread . . . . (related to MUMPS).
I've been experimenting over the past year with MUMPS and PaStiX for parallel LU, and found MUMPS pretty much useless because it uses so much memory. PaStiX was vastly superior performance-wise and it supports hybrid threads-MPI, which I think is essential for parallel LU solvers to make good use of typical multi-socket multi-core compute nodes. The interface, build and documentation are a bit clunky (I put the last point down to developer language issues), but the performance is good and the developers are responsive. I benchmarked PaStiX for P1 and P2 3D linear elastic finite element problems against a leading commercial offering, and PaStiX was marginally faster for P1 and marginally slower for P2 (PaStiX performance does depend heavily on BLAS). I couldn't even compute the test problems with MUMPS because it would blow out the memory. For reference, I tested systems up to 27M dofs with PaStiX. Based on my experience and tests, I'd be happy to see PETSc drop MUMPS and focus/enhance/fix support for PaStiX. Garth
