<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">Hi,</div><div class=""><br class=""></div><div class=""> I am solving a transonic Euler flow problem discretized with SUPG. The mesh is made of Tet4 elements and there are about 7M dofs, which I am trying to solve over 192 cores. </div><div class=""><br class=""></div><div class=""> I had earlier written about the linear solver returning with Inf, and have since moved beyond that such that I am able to get a solution with the following command line parameters:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-size: 10px; font-family: Monaco; color: rgb(245, 245, 245); background-color: rgb(0, 0, 0);" class="">-ksp_gmres_restart 100 -pc_type asm -sub_pc_type ilu -sub_pc_factor_levels 4 -sub_ksp_type preonly</div></div><div class=""><br class=""></div><div class=""> The problem now is that I am limited to very small time-steps (~10e-6), outside of which the solver starts to choke and the solution diverges. I have tried other command line options and this above combination is what seems to provide the best possible solution strategy, albeit constrained in time steps. </div><div class=""><br class=""></div><div class=""> I would appreciate any recommendations on solver configurations that may allow me to take larger time-steps. </div><div class=""><br class=""></div><div class=""> Would coding up AMG be a possible alternative (more robust and dependable)? </div><div class=""><br class=""></div><div class=""> Please let me know if you need additional information. </div><div class=""><br class=""></div><div class="">Regards,</div><div class="">Manav</div><div class=""><br class=""></div></body></html>