Hello Kuark, Typically we see no benefit using hyperthreads due the nature of the workload of our scientific codes.
So I will only describe things without hyperthreads (which mostly just add a complications). With that in mind simfactory's './simfactory/bin/sim setup-silent' should do a good job at setting up a default machine description. When you submit you should set ppn-used to the number of compute cores you will use, one per OS thread. So with 16 threads you would use ppn-used to 16 as well. If you are looking to get most speed on a typical workstation (single node) then most likely you fastest way is actually to use 1 thread per MPI rank and as many MPI ranks as you have physical cores. So something like: --cores 6 --num-threads 1 --ppn-used 6 in your case. Yours, Roland > Hello everyone! > > > > > I’m new to the ET. I have the ET installed on my desktop. It has one > Intel(R) Core(TM) i5-10500 CPU with 6 physical cores and two threads > per single physical core (but according to the Ubuntu’s conventions, > the computer has 12 processors in total, as shown in the attachment > of this email) and it also has Ubuntu 20.4. So I wonder whether you > could please tell me how to set the correct parallel parameters for > ET simulations, such as the options of the submit command > ./simfactory/bin/sim (--cores, --num-threads and –procs) and the > initial values of the file <username>.ini (pn, max-num-threads, > num-threads, nodes). > > > > > > Up till now, I have tried many possible combinations without success. > It usually returns messages like “Warning: Too many threads per > process specified: specified num-threads=16 (ppn-used is 1)”, > “Warning: Number of used cores per node, number of SMT threads, and > number of threads per process are inconsistent: ppn-used=1, > num-smt=1, num-threads=16_threads (ppn-used*num-smt must be an > integer multiple of num-threads)” and “Warning: Total number of > threads and number of threads per process are inconsistent: procs=1, > num-threads=16 (procs*num-smt must be an integer multiple of > num-threads)” and doesn't start running. > > > > > > I know parallelization plays a very important role in massive > numerical computations like the ET. However, I’m very confused by > many of the concepts it uses. I don’t find a documentation for these > parameters after browsing websites (like > https://urldefense.com/v3/__https://bitbucket.org/simfactory/simfactory2/src/master/doc/userguide/__;!!DZ3fjg!-V4c4apw4yKOJIfbQ1lrgx6hPKu9LiVqj0ILFwv_OEVnXTWKSbPZC8pb0g9powxNY4YgaE9EJD1NMwfPeCp1DnSGG_eq$ > , > https://urldefense.com/v3/__https://simfactory.org/info/documentation/__;!!DZ3fjg!-V4c4apw4yKOJIfbQ1lrgx6hPKu9LiVqj0ILFwv_OEVnXTWKSbPZC8pb0g9powxNY4YgaE9EJD1NMwfPeCp1DukO6jh5$ > , > https://urldefense.com/v3/__http://einsteintoolkit.org/usersguide/UsersGuide.html__;!!DZ3fjg!-V4c4apw4yKOJIfbQ1lrgx6hPKu9LiVqj0ILFwv_OEVnXTWKSbPZC8pb0g9powxNY4YgaE9EJD1NMwfPeCp1DhQA-A7m$ > or even in the source code in the directory > “./simfactory/lib/”). There are merely some hints in the > jupyter tutorial “CactusTutorial.ipynb”. > > > > > > > > Kuarks -- 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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