Originally posted by: Max518

Hello, everyone

I'm now solving my MIP formulation by CPLEX (IBM ILOG OPL IDE Version:6.3).

When I implemented it on small-scale problem, it can work well and fast.

However, for large-scale problem, the "out of memory" problem turns up.

 I changed some parameters in the settings:
1.Node storage file switch->3, node file on disk and compressed
2. MIP node selection strategy->2, best estimate search
3. MIP variable selection strategy->3, strong banching
4. Memory available for working storage: 8000
5. Memory reduction switch->true

However, the problem cannot be solved.

Would you please give me some advice to solve this problem? Thank you very much.

Hi

have you tried

cplex.thread=1;

regards

Originally posted by: Max518

Hi

i have tried this method, but it did not work.

Hi,

have you tried with 12.6.2 which is more recent than 6.3 ?

regards

Originally posted by: Max518

Yes, i have tried the new version. The problem still exist.

Hi,

have you checked that your model is a good model ?

Maybe you should improve your model.

What about a medium size problem that could help you tune your model ?

regards

Originally posted by: Max518

Hi,

the CPLEX can program the medium size problem but failed to find the solution.

could you give me some advices?

best regards

Hi,

maybe you could have a look at the white paper Efficient modeling with the IBM ILOG CPLEX Optimization Studio that you may get over the internet

regards

Originally posted by: Max518

Than you so much, Alex.

Hi,

you re welcome.

In our Virtual User Group : https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/W1a790e980a7d_49c5_963d_2965e5d01401/page/Virtual%20User%20Group%20Meetings

you will see:

Efficient modeling with OPL - Optimization Programming Language Tips and Tricks

A video is available at

https://www.ibm.com/developerworks/community/groups/service/html/communityview?communityUuid=3a298dfa-4726-466f-9cee-cbc6221b8bba#fullpageWidgetId=W44fb1fc117db_4d8f_baba_82cb1efe678c&file=cd501635-644e-4ed6-a981-01ef7870e52b

regards