[Pw_forum] Optimal number of CPUs

[Ihor Kupchak]

Dear pwscf users!
I run CP calculation with parallel version 3.2. Using 16 CPUs I got only 1.8 time/step improvement comparing with “serial” mode and the same input. Is this improvement normal? Haw many CPUs I have to use to get an optimal result? In general, what is the principle haw to choose processors number? Thank you.

Ihor Kupchak
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University of Ontario Institute of Technology
2000 Simcoe Street North, Oshawa, Ontario, Canada L1H 7K4