[QE-users] QE 7.2: performance degradation for isolated systems?

[Paolo Giannozzi]

Please provide inputs and outputs

On 4/28/23 11:41, Tom Demeyere via users wrote:
> Dear users,
> 
> Yesterday I wanted to perform a small calculation on a centred Pt13 
> nanoparticle in a 20 Å box, I tried QE 7.1 and QE 7.2 with the exact 
> same input, hardware and parallelisation parameters. 7.2 end up being 
> much slower:
> 
> QE 7.1:
> 
> 15th iter: 100.5 secs
> 30th iter: 184.2 secs
> 
> QE 7.2:
> 
> 15th iter: 463.5 secs
> 30th iter: 824.4 secs
> 
> But QE 7.2 converge the SCF in fewer steps (still ends up being much 
> slower). I reproduced this behaviour on 2 other machines and playing 
> with parallelisation parameters doesn’t change anything. How to explain 
> this?
> 
> Best regards,
> Tom Demeyere
> 
> 
> 
> 
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-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222