Originally posted by: AllanHunter

Hi,

I'm using OPL of IBM ILOG Cplex Optimization Studio Community version 12.6.3.0 on a 64 bit machine, under Win7 SP1.

My model is a CP one, with 65 variables and 136 constraints. (this is small, but the model looks pretty hard to solve)

After 4 hours or so, the statistics show that the Choice Points, Number of Branches and Number of Fails reach the same limit of 2147483647.

The memory usage stays almost constant and very limited: 90 Mb.

In the OPS settings for Constraint Programming/Search Control/Limits , I cannot increase the limits beyond 2147483647

So, I have 3 questions:

1. Is this limit intrinsic to Cplex due to a 32 bit counter ?  (I have installed the 64 bit version from the downloaded file COSCE1263WIN64.exe )

2. Even after these limits are reached, the CP optimizer seams to continue working... is this true or is it definitely blocked by these limits ?

3. How can I check that I'm running the 64 bit version of Optimization Studio ?

Hi

for big values instead of using the ops editor you should use scripting:

execute

{

cp.param.branchlimit=1000000;

cp.param.faillimit=100000;

}

A way to check whether you run in 32 or 64 bits is to do

int a=maxint;
execute
{
a;

}

If in the problem browser you see 9007199254740991 then you run 64 bits

regards

Originally posted by: AllanHunter

I've added :

    cp.param.branchlimit=4000000000;
    cp.param.faillimit = 4000000000;
    cp.param.choicepointlimit = 4000000000;

to the (pre-processing ?) execute block, the one preceding the declaration of dvars and  the 'subject to' statement,

It seems to work as the engine log clearly states:

 ! Satisfiability problem - 65 variables, 136 constraints
 ! FailLimit            = 4 000 000 000
 ! ChoicePointLimit     = 4 000 000 000
 ! LogPeriod            = 1 000 000
 ! SearchType           = Restart
 ! RestartFailLimit     = 60
 ! BranchLimit          = 4 000 000 000

Also, I get 9007199254740991  for 'a' when running the suggested test model.

Thank you for your time !