Recommended pardiso settings for high accuracy solutions

[bill_tm]

hi,

i want to get high accuracy solutions for symmetric indefinite matrix equations, mtype = -2, using direct solver parallel pardiso.

i know to use iparm(8) = negative for extended precision but what other values of iparm vector are best in this case.

thank you for your suggestions.

[VarshaS_Intel]

Hi Bill Adams,

Thanks for posting in Intel Communities.

Could you please try specifying the iparm[12] to get better accuracy? Please find the below link for more details regarding the significance of iparm[12] and other iparm components.

https://www.intel.com/content/www/us/en/develop/documentation/onemkl-developer-reference-c/top/sparse-solver-routines/onemkl-pardiso-parallel-direct-sparse-solver-iface/pardiso-iparm-parameter.html

In addition, could you please let us know your use case and OS details you are using? It will help us in understanding the issue better and helps you accordingly.

Thanks & Regards,

Varsha

[bill_tm]

Hi Varsha

On Windows 10 using mkl 2023 and interested in accuarcy of sparse solvers for indefinite and positive definite symmetric matrices.

I will use your suggestion of iparm[12]. Is there anything else you suggest.

Thank you.

[VarshaS_Intel · Accepted solution]

Hi Bill Adams,

Could you please let us know if you are able to get the expected accuracy using iparm[12]? If not, could you please provide us with the complete sample reproducer code to investigate more on your issue more?

Thanks & Regards,

Varsha

[bill_tm]

Hi Varsha

your suggestion is good and the accuracy is good thank you.

[VarshaS_Intel]

Hi Bill Adams,

Glad to know that your issue is resolved. Thanks for accepting our solution. This thread will no longer be monitored by Intel. If you need any other information, please start a new question.

Have a Good Day!

Thanks & Regards,

Varsha