Querry about multiple job submit in single node, not getting full CPU time

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I am using
gmx mdrun -v -deffnm npt -nt 8 -pin on -pinoffset 0 &
gmx mdrun -v -deffnm npt -nt 8 -pin on -pinoffset 8 &
this two command line in a single node workstation where i have total 16 physical core and 32 logical core i.e 2 thread per core.
But When I am trying to monitoring how much cpu time it is getting, during that time I found that both the job getting cpu time less than 800 percent. Ideally it should get 800 percent since i am using 8 thread for each job and also i have done pinning. So can you please explain why this is happens. Or if i am doing something wrong or my understanding is wrong then please explain what is going wrong.