Calculating on Multiple Cores
Ongoing
Hello everybody.
I have got a MIP model that takes Gurobi 9 days to solve on 4 cores
on a 24-core-machine it is still running after 10 days
What is going wrong?
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Hi Theresa,
Do you mind sharing log files of these runs? Please note that it's not always guaranteed to get a performance increase when using more cores. Often there are other limiting factors like single-core performance or memory throughput.
Cheers,
Matthias0 -
Hi Matthias.
Well, the problem is that I can not directly interact with gurobi as there is an other framework in between. So I can not see the progress right now.
It is actually using a lot of RAM.
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Well, then I don't think we can help you very much, Theresa. It seems you are solving a pretty hard model and sometimes this does take a lot of time.
I suggest creating a smaller version of that model and check for some parameter tuning opportunities.
You should definitely try to inspect the log file of that 9-hour run to find some clues about performance bottlenecks.
Cheers,
Matthias0 -
Hi.
Okay. I also have another model that takes about 5 hours on a 4-core-workstation. On a cluster (24-core-machine) it is still running after 20 hours using 40 GB RAM on average. Gurobi "is designed to effectively exploit multiple cores". Why are more cores less efficient?
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