ILOG CPLEX 11.0 User's Manual > Discrete Optimization > Solving Mixed Integer Programming Problems (MIP) > Troubleshooting MIP Performance Problems > Large Number of Unhelpful Cuts

Large Number of Unhelpful Cuts

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While the cuts added by ILOG CPLEX reduce runtime for most problems, on occasion they can have the opposite effect. If you notice, for example, that ILOG CPLEX adds a large number of cuts at the root, but the objective value does not change significantly, then you may want to experiment with turning off cuts selectively (that is, by type of cut) or completely.

To turn off cuts selectively, use the cut parameters summarized in Table 14.9, with a value of -1 (minus one). For example, in the Interactive Optimizer, the following command turns off only cover cuts: 

set mip cuts covers -1

To limit types of cuts generated, consider the parameter EachCutLim, CPX_PARAM_EACHCUTLIM.

To limit the number of passes that ILOG CPLEX executes to generate cuts, consider the parameter CutPass, CPX_PARAM_CUTPASS.

To turn off all cuts, set the cut pass parameter to -1 (minus one). For example, in the Interactive Optimizer, use the following command to turn off all generation of all cuts:

set mip cuts all -1

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