during compilation the number of threads of the build machine is hardcoded into the code: gcc ... -DMAX_CPU_NUMBER=4
apparently the ubuntu build machine had two cores with these type of libraries it is always better to build them on the machine your are using them one so you get the optimal performance. binary packages can only provided the lowest common denominator. ** Changed in: openblas (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/817212 Title: Number of threads stuck on two To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openblas/+bug/817212/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs