Hydrology 3 Posted August 5, 2020 Report Share Posted August 5, 2020 I don't know if this should be under the MODFLOW directory, but I have been trying to see if I can speed up my GMS runs. I have a GMS MODFLOW model that is taking about an hour to run and I would like to shorten that run time. I see that I am using about 2.5% of my CPU utilization and I am running about 300 kB/s in disk access time, well below the capacity of the CPU or disk. I have a dual processore Xeon system with 12 cores for each processor running at 3.2GHz. My disk drive is 4-2TB M.2 NVME SSD's running in a Raid 0 array in a PCIe slot. The system has 256GB of RAM. This configuration gives me about an hour run time for the model. I tried loading the whole model into a 90Gig RAM Disk on the same machine, and the run time was basically the same. As a comparison, I ran the same model on my laptop that has 16GB of RAM and a single 1TB NVME drive and a single i7 4 core processor. The model actually ran about 10% faster on my laptop than on my workstation. What is the slow link in the model execution? It doesn't seem to be CPU or disk access. Is there anything that I could do (hardware wise) to speed the model run up? Quote Link to post Share on other sites
C. Moebus 1 Posted August 6, 2020 Report Share Posted August 6, 2020 (edited) The slow link in the model execution is most probably that you are not using a parallel version of MODFLOW (Check option in MODFLOW Global/Basic Package) or a not parallelised solver (LMG or PCGN). 2 x 12 processors = 24 processors - makes a max. of 4% usage per core if not parallelised... Edited August 6, 2020 by C. Moebus Quote Link to post Share on other sites
Hydrology 3 Posted August 6, 2020 Author Report Share Posted August 6, 2020 Hi thanks for responding. I have the 64bit option and parallel option checked. I am using the PCG package. Has the PCG package not been parallized? Quote Link to post Share on other sites
Hydrology 3 Posted August 8, 2020 Author Report Share Posted August 8, 2020 (edited) I tried the PCGN solver and it was awesome to see it use 90% of my 24 cores. But, strangely the PCGN took 17 hours to run using all 24 cores, where the PCG solver only took 30 minutes to run basically using one core. Edited August 8, 2020 by Hydrology Quote Link to post Share on other sites
C. Moebus 1 Posted August 10, 2020 Report Share Posted August 10, 2020 Have you tried the LMG-solver instead? The PCGN-solver did not convince me mostly.. Quote Link to post Share on other sites
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