I am solving K*D=F equation with pardiso sparse solver. K is a 11000*11000 sparse symmetric matrix and F is also sparse matrix with 11000*363 dimensions. On a dell computer with Intel Core 2 Duo CPU and MKL version 10.0.1 it takes 2.2 seconds to solve the equations. I am using default parameters for the solver and I tried both sequentional and multi-threading options but I can not improve the performance time. I found that the performance is very sensitive to the number of RHS:
Number of RHS=363, Time=2.21 seconds
Number of RHS=120, Time=0.53 seconds
Number of RHS=30, Time=0.19 seconds
Number of RHS=9, Time=0.06 seconds
Why there is much difference in performance?! In my program number of RHS can be between 1-1000 for different situations. Is there any way to speed up the process for high number of RHS?
If I switch to the new version of MKL can I get significant improvement?
Thank you in advance for your help.