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Journeyman III

Low CPU occupation found on A Workstation with 2 * EPYC 7H12


  Does EPYC 7H12  Support MPI simulation (ANSYS CFX, FLUENT, ICEPAK )?

Recently, I tried to run a CFD calclation (16 threads chosed for parallel computation )on a worksation with EPYC 7H12 *2 , 256GB RAM.  

In the task management , I found that ONLY 0.5% usage was occupied for each thead?  

How can I fix this problem? Is there anyone facing the same kind of problem now?Task management.png

2 Replies
Journeyman III

Judging by the ratio of the share of employment per core, Hyper Transport is enabled for both processors, a quite expected value with the number of threads 100/2*64*2=0.4% (Windows10 or Server2019 and later slightly overestimates the thread's core/thread usage).

Both in the case of AMD and in the case of Intel for 2 or more processor systems, it is necessary to turn off HyperTrasport/HyperTreating for efficient calculation, otherwise there will be no gain in comparison with a single CPU. OS exclusively windows server, no windows 10.


From my experience, it is based on a 2-processor LGA-3647 system. There should be the same regularity for 2 processor AMD systems.

Big Boss

andy_gore, people here know a little about Ryzen, For EPYC users there is a EPYC forum in the Comunity Enjoy, John.