<div dir="ltr"><span style="font-family:arial,helvetica,sans-serif;font-size:13px">Hello IPOPT community,</span><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px"><br></div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px">I am on Ubuntu 14.04 using precompiled binaries of IPOPT 3.12.3 that come with CasADi package. I observed that changing linear algebra solver in IPOPT to HSL maXX family does not bring any effect on performance. Whereas the very same code built on MAC OS 10.11 runs 2-3 times faster with 'ma97' than with 'mumps' linear solver. I should say the two computers are physically different but both have Intel Core i7 2.8GHz on them.</div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px"><br></div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px">Changing OMP_NUM_THREADS seems to be bringing no effect, as well as changing compiler optimisation flags for both my code and HSL library. I suspect that parallelisation might not work properly.</div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px"><br></div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px">Did anyone encounter similar problems?</div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px"><br></div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px"><br></div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px">Best regards,</div><div style="margin:0px;padding:0px;border:0px;font-family:arial,helvetica,sans-serif;font-size:13px">Peter</div></div>