How is the parallel parameter set in the computation? To enable the parallel in teh phase 1, it needs to set the iparm(2) as 3:
If iparm(2) = 3, the parallel (OpenMP) version of the nested dissection algorithm is used. It can decrease the time of computations on multi-core computers, especially when PARDISO Phase 1 takes significant time.
The default value of iparm(2) is 2