Hi Roland, Thanks for your reply. You touch on an important point, i.e the cluster's billing policy, that hadn't crossed my mind.
>From the billing policy of Leonardo, it seems that it is possible to use only >a fraction of a node's total CPUs. https://docs.hpc.cineca.it/hpc/hpc_intro.html#billing-policy However, the documentation also stresses that: ...if a job reserves all of a node’s RAM — even without utilizing all its CPUs — the node becomes unusable for other jobs and is therefore billed accordingly. So, apart from the cores requested, should I also try to calculate the RAM requirements? For example, I see that Bruno's "leonardo-dcgp.ini" file specifies: memory = 494000 And the respective submitscript also has this line: #SBATCH --mem 494000MB I note that each node in Leonardo has 512GB of RAM, so that means that the script requests ~94.2% of the RAM. I am not sure I follow the reasoning behind this. What is the default behavior of SimFactory if I were to remove the above specifications from the config files? Because, if by default Simfactory requests/uses all the RAM available in a node, then as far as I understand, it does not make sense to request fewer cores than a full node. Let me know what you think. Best, Panayotis ________________________________ From: Roland Haas <rh...@mail.ubc.ca> Sent: Friday, September 26, 2025 4:31 PM To: Bruno Giacomazzo <bruno.giacoma...@unimib.it> Cc: IOSIF PANAGIOTIS <panagiotis.io...@units.it>; Einstein Toolkit Users <users@einsteintoolkit.org> Subject: Re: [Users] Inconsistency warnings: cores/threads mismatch [Leonardo cluster] Hello all, > I never used --cores and I don't know the difference with procs. --cores is a synonym for --procs in simfactory. The hope was to avoid the confusion of "procs" being "Processes" or "Processors". Though it has been pointed out that the best name would actually be "--threads" since that is what simfactory actually starts, which then collides with "--num-threads" (threads per process). Does Leonardo actually charge you for partial nodes if you do no use a full one? Simfactory is mostly written under the assumption (true at the time) that HPC systems would give you full nodes all the time, so if you use 1 core or 112 cores of a node, the charge would be the same (though shared node systems are becoming more common for HPC now [or again]). Yours, Roland -- My email is as private as my paper mail. I therefore support encrypting and signing email messages. Get my PGP key from http://pgp.mit.edu .
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