I'm not completely sure andI need to check it out.But the solver step for your system generallytakes
Time solve : 0.036523 s
So2 CGS iterations should take about 0.072 plus somevery small time for additonal computation.I'd estimatethe upper limit for CGS as 0.1 sec.In your log I see
iterative : 31 1
================ PARDISO: solving a real nonsymmetric system ================
Summary PARDISO: ( factorize to solve )
Time cgs : 0.203449 s cgx iterations 2
It might be the statistics is wrong (say the number iterations is not correct) or PARDISO recomputed the LU factors.
All the best
Sorry for the delay taken in answering and many thanks for providing the test code.
The last usage model is correct.
I investigated you code and I've not found any bug in PARDISO. To improve the performance of your code. I'd reccomend to use the parallel METIS by setting iparm(2)=3 and it essentiallyreduces the reordering time.
Your code also work well if we turn off scaling and matching by setting
iparm(11) = 0 ! Scaling vector
iparm(13) = 0 ! improved accuracy using (non-)symmetric weighted matchings
It looks like your system is well-conditioned but I'd rather check how it works in the whole application.
I'll let you know if I found further performance improvements.
All the best