Re: [Help-glpk] MIP performance in last GLPK versions

[Andrew Makhorin]

> I have a question regarding performance of MIP solving with GLPK
> versions 4.20 and 4.25 . 

> I do some experiments with a MIP model for production location
> optimization and observed 
> that the performance went wrong from 4.20 to 4.25. 

> I compiled both versions in the same way, on a WinXP PC with Cygwin
> distribution. 
> I have installed and compiled gmp 4.2.1. which is strongly recommended
> during configuration 
> of the distribution. 

> With 4.20 my model with the reference data set was solved in 105 seconds
> using 5 MB. 
> 4.25 needs 275 seconds and 69 MB memory: 

In 4.20 (and earlier versions) the default branching strategy was the
best projection heuristic (--bestp); in 4.21 it was changed to the best
local bound (--bestb), because the latter is more appropriate for the
branch-and-cut method.