mpir runs slow after reboot. What is the reason?

I reboot my workstation and resubmit a job that ran earlier.
This time the jobs run even slower.

What puzzles is that the ps -ef info gives:

Quote:

centguy 3995 3989 30 17:32 pts/1 01:32:13 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 3996 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 3997 3989 27 17:32 pts/1 01:23:27 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 3998 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 3999 3989 30 17:32 pts/1 01:32:45 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4000 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4001 3989 85 17:32 pts/1 04:21:07 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4002 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4003 3989 35 17:32 pts/1 01:49:18 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4004 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4005 3989 32 17:32 pts/1 01:40:04 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4006 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4007 3989 56 17:32 pts/1 02:52:21 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4008 3989 99 17:32 pts/1 05:07:02 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4009 3989 26 17:32 pts/1 01:22:39 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4010 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4011 3989 46 17:32 pts/1 02:22:48 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4012 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4013 3989 29 17:32 pts/1 01:30:59 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4014 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4015 3989 50 17:32 pts/1 02:35:04 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4016 3989 2 17:32 pts/1 00:07:04 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4017 3989 49 17:32 pts/1 02:32:40 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4018 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4019 3989 50 17:32 pts/1 02:35:18 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4020 3989 2 17:32 pts/1 00:07:08 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4021 3989 32 17:32 pts/1 01:39:35 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4022 3989 97 17:32 pts/1 04:59:59 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4023 3989 58 17:32 pts/1 02:58:51 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4024 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4025 3989 34 17:32 pts/1 01:47:15 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std centguy 4026 3989 99 17:32 pts/1 05:07:03 /install-linux-ifort/vasp.5.4.1-2019-06/bin/vasp_std

Is this a hardware problem or the software problem?
But the OS runs fine.. Why would a core takes up only 1H+ while others 5H+?

Really bizzare!