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Slow MIPS Performance

Ongoing

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1 comment

  • Matthias Miltenberger
    Gurobi Staff Gurobi Staff

    Hi Animesh,

    What makes you think that this is "poor" performance? Just because a model isn't huge doesn't mean that it is easy to solve. From the log, you can see that Gurobi is making steady progress to close the gap after quickly finding a good solution. Often, proving optimality is pretty tough and can result in a large tree even if the optimal solution has been found early.

    For an extreme example, I can recommend the MIPLIB 2017 instance ej. This instance only has 3 variables and one constraint and if you don't solve it in presolving (with Gurobi you need to set Presolving=0), you will build up a very huge tree with very slow progress.

    You might want to look into your model to improve its formulation. Maybe you can find a different way to express the underlying problem and to tighten the LP relaxation.

    Cheers,
    Matthias

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