"reading solution for model" - What happens here?
Posted: Tue Nov 20, 2018 11:41 am
Hello everyone,
I have a question regarding the solving process of GAMS. I have an MILP-Model and I am using the CPLEX-Solver. I run a Loop in GAMS to solve for different model variations. The model runs and produces optimal results but the run-time is very long.
In the log-file I can see the following:
Fixed MIP status(1): optimal
Cplex Time: 7.47sec (det. 2575.80 ticks)
Proven optimal solution.
MIP Solution: -370160.220173 (3161 iterations, 0 nodes)
Final Solve: -370160.220173 (4350 iterations)
Best possible: -370160.220173
Absolute gap: 0.000000
Relative gap: 0.000000
--- Restarting execution
--- SpeicherOptMFH.gms(842) 555 Mb
--- Reading solution for model Modell_SBSopt
--- SpeicherOptMFH.gms(764) 762 Mb 2220 secs
You can see, Cplex finds the optimal solution after around 7 sec. But, "reading solution" takes around 40 minutes...
I wanna know, what happens at "reading solutions" and is there a way to shorten the computation time. Additionally for my results, I don't need to know all the variables, just a small selection.
Maybe there is someone who could help me?
Thank you very much.
Cheers,
Fritz
I have a question regarding the solving process of GAMS. I have an MILP-Model and I am using the CPLEX-Solver. I run a Loop in GAMS to solve for different model variations. The model runs and produces optimal results but the run-time is very long.
In the log-file I can see the following:
Fixed MIP status(1): optimal
Cplex Time: 7.47sec (det. 2575.80 ticks)
Proven optimal solution.
MIP Solution: -370160.220173 (3161 iterations, 0 nodes)
Final Solve: -370160.220173 (4350 iterations)
Best possible: -370160.220173
Absolute gap: 0.000000
Relative gap: 0.000000
--- Restarting execution
--- SpeicherOptMFH.gms(842) 555 Mb
--- Reading solution for model Modell_SBSopt
--- SpeicherOptMFH.gms(764) 762 Mb 2220 secs
You can see, Cplex finds the optimal solution after around 7 sec. But, "reading solution" takes around 40 minutes...
I wanna know, what happens at "reading solutions" and is there a way to shorten the computation time. Additionally for my results, I don't need to know all the variables, just a small selection.
Maybe there is someone who could help me?
Thank you very much.
Cheers,
Fritz