Computational time of model extremely increased

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PeterBe
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Computational time of model extremely increased

Postby PeterBe » 1 week ago

Hi guys,

I am using GAMS with CPLEX as the solver. I have a really strange problem. I have a MIP model with many binary vairables which was solved within 5 minutes.

All of a sudden - without having changed anything - the same model requires quite much time to be solved. I let the solver run for 5000 seconds, but still the problem was not solved (meaning that the Gap of the best found solution is still quite high).

Has someone experienced something similar? Or could someone think about a possible reason for that? I uploaded the node log file of that run. Maybe someone of you will see something interesting in it.

Thanks a lot in advance for your comments.
Attachments
Log3 - Time 5000.txt
Node Log File
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PeterBe
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Re: Computational time of model extremely increased

Postby PeterBe » 1 week ago

Does nobody have a clue?

Do you think the I should let the model run for more than 5000 Seconds? The improvement for the last 3000 senconds were 0 % with regard to the gap (sett uploaded logfile). This is why I stronlgy doubt that a higher runtime will significantly improve the results.

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Gideon Kruseman
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Re: Computational time of model extremely increased

Postby Gideon Kruseman » 6 days ago

same model and same data?
Gideon Kruseman
ex-ante and foresight lead @CIMMYT, big data focal point @CIMMYT, coordinator CoP socio-ecnomic data @CGIAR_BigData

akerdeth
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Re: Computational time of model extremely increased

Postby akerdeth » 1 hour ago

Hi PeterBe,
I get the same error in my simulation. Did you find any solution about?

Larissa
Thank you.


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