[Pw_forum] QE 6.0 slower than 5.4 ??

[Francesco Pelizza]

Hi Dear community,


I have a question...Since the qe 6.0 release i started to use it, and I 
noticed a slow down for systems up to 48 atoms / 100 electrons running 
on few cores, and a speed up running upon more cores.

I other words, taking as example an insulator polymer, set in its 
lattice with 96 electrons:

using qe 5.4 on 8 threads takes 25-35% less time than qe 6.0

that's generally true from scf, to vc-relax to bands and phonon or 
whatever calculations

if I scale on servers or HPC I do not see slow down, and perhaps the qe 
6.0 is in the average 10-15% faster.


Was it expected to be so?

Something changed in the way the system is fragmented across threads?


BW

Francesco Pelizza

Strathclyde University