Optimizer options

Introduces the options available in CPLEX.

This manual explains how to use the LP algorithms that are part of CPLEX. The QP, QCP, and MIP problem types are based on the LP concepts discussed here, and the extensions to build and solve such problems are explained in the CPLEX User’s Manual.

Default settings will result in a call to an optimizer that is appropriate to the class of problem you are solving. However, you may wish to choose a different optimizer for special purposes. An LP or QP problem can be solved using any of the following CPLEX optimizers: dual simplex, primal simplex, barrier, and perhaps also the network optimizer (if the problem contains an extractable network substructure). Pure network models are all solved by the network optimizer. QCP models, including the special case of SOCP models, are all solved by the barrier optimizer. MIP models are all solved by the mixed integer optimizer, which in turn may invoke any of the LP or QP optimizers in the course of its computation. The table titled Table 1 summarizes these possible choices.
Table 1. Optimizers
  LP Network QP QCP MIP
Dual Optimizer yes   yes    
Primal Optimizer yes   yes    
Barrier Optimizer yes   yes yes  
Mixed Integer Optimizer         yes
Network Optimizer Note 1 yes Note 1    
Note 1: The problem must contain an extractable network substructure.

The choice of optimizer or other parameter settings may have a very large effect on the solution speed of your particular class of problem. The CPLEX User's Manual describes the optimizers, provides suggestions for maximizing performance, and notes the features and algorithmic parameters unique to each optimizer.