Decision Optimization

Decision Optimization

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  • 1.  I got two different running time. Which is CPU time?

    Posted 03/04/15 07:36 AM

    Originally posted by: 9050_Zhihai_Zhang


    I solved a model by Cplex124 in ubuntu14.04 OS. The setting is as follow:

    cplex.setParam(IloCplex::ClockType,1);
    cplex.setParam(IloCplex::TiLim,28800);
    cplex.setParam(IloCplex::Threads,1);
     

    However, two different running times were obtained. 

    1. The first one is :

    Root node processing (before b&c):

      Real time             = 28805.22
    Sequential b&c:
      Real time             =    0.00
                              -------
    Total (root+branch&cut) = 28805.22 sec.
     

    2. The second was obtained by invoking function getTime() and its value is 32147.3 sec. 

     But, what's means of the first time, 28805.22 sec, which is approximated to the time limits. So, I guess CPU time should be 28805.22 sec.   But according to the CPLEX help document, I know that getTime returns CPU time. what's problem? which one is the exact CPU time that can be used to indicate performance of  CPLEX?

    Thanks in advance.

     

     

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  • 2.  Re: I got two different running time. Which is CPU time?

    Posted 03/06/15 01:29 AM

    The time returned by IloAlgorithm::getTime() is the time since the last reset (see the reference documentation). Maybe you did not reset right before calling solve()?


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