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Release Notes

Major releases contain substantial changes to the GAMS system. The License Check date is set to the release date of the major release.

Minor releases are mainly issued to provide bug fixes, performance improvements, and maintenance releases of solver libraries. Additionally, they can provide a few new features that do not change existing behavior. The License Check Date remains the same as for the prior major release. This means that any license file that worked with the prior major release will also work with this minor release.

Maintenance releases do not provide any new features. They are issued to provide bug fixes, performance improvements, and maintenance releases of solver libraries. The License Check Date remains the same as for the prior major release. This means that any license file that worked with the prior major release will also work with this maintenance release.

GAMS Distribution 23.0

Distribution History

23.0.2 (Major release) February 14, 2009

GAMS Major Release 23.0.2 - February 14, 2009

Acknowledgments

We would like to thank all of our users who have reported problems and made suggestions for improving this release. In particular, we thank Surendu Korgaokar, Tom Rutherford, Stefan Vigerske and Rich Roberts.

GAMS System

GAMS Data Utilities

GDXXRW
  • Fix to not limit the size of the block read to 65536 lines

Documentation

  • Updated McCarl GAMS User's Guide

Other

As announced earlier we dropped the following systems as of this GAMS Distribution.

  • GAMSBAS: The newer savepoint/loadpoint facility is easier to use and more robust.
  • MPSWRITE: The newer CONVERT utility includes this capability

Model Libraries

GAMS Model Library

  • poutil (342): Portfolio Optimization for Electric Utilities

GAMS Test Library

Solvers

As announced in the 22.9 release notes we dropped the following solvers as of this GAMS Distribution.

  • CONOPT1 (old version of CONOPT). The default CONOPT version, CONOPT 3, will not be dropped.
  • MILESOLD (old version of MILES). The default MILES version will not be dropped.
  • OSL1 and OSL2 (old versions of OSL). The default OSL version will not be dropped.
  • PATHOLD (old version of PATH). The default PATH version will not be dropped.

Due to user requests, and despite our earlier announcement, we did not drop the following components:

  • CONOPT 2 (old version of CONOPT).
  • DEA

CPLEX

New libraries 11.2.1

GUROBI

The new Gurobi solver provides state-of-the-art simplex-based linear programming (LP) and mixed-integer programming (MIP) capability.

The Gurobi MIP solver includes shared memory parallelism, capable of simultaneously exploiting any number of processors and cores per processor. The implementation will be deterministic: two separate runs on the same model will produce identical solution paths.

The Gurobi solver is available for the 32-bit and 64-bit versions of Windows and Linux. Please contact us for an evaluation license.

KNITRO

New libraries 5.2.0

LINDOGLOBAL

New libraries 5.0.1.345

MOSEK

New libraries 5.0 rev 112

XPRESS

New libraries 19.00.04

  • The primal algorithm has been improved and is now 40% faster on XPRESS' LP benchmark test set and 20% faster on XPRESS' large LP benchmark test set.
  • The dual algorithm has been improved and is now 22% faster on XPRESS' LP benchmark test set and 45% faster on XPRESS' large LP benchmark test set.
  • The MIP performance has been improved and is now 40% faster on XPRESS' MIP benchmark test set
  • Improvements to the Quadratic Primal algorithm to avoid cycling problems

In-core communication solver links

  • Support of GUROBI as an in-core communication solvers.
  • Experimental in-core link MINOSD
  • Enhancements and bug fixes for the in-core communication solver links BDMLPD, CONOPTD, and CPLEXD

Where a traditional link already exists, the newer in-core link version has a "D" appended to the name (D for DLL). These in-core links are very similar to their traditional predecessors. They may lack some functionality but offer in-core communication between GAMS and the solver, making potentially large model scratch files unecessary. This can save time if you solve many models in your GAMS program.

Solver/Platform Availability Matrix

Solver/Platform availability - 23.0    February 14, 2009
  x86
MS Windows
x86_64
MS Windows
x86
Linux
x86_64
Linux
Sun Sparc
SOLARIS
Sun Sparc64
SOLARIS
Sun Intel
SOLARIS
IBM RS-6000
AIX 4.3
Mac PowerPC
Darwin
Mac Intel32
Darwin
HP 9000
HP-UX 111
SGI
IRIX2
DEC Alpha
Digital Unix 4.03
ALPHAECP X X X X X X X X X X     X
BARON 8.1 X 32bit X 32bit       X          
BDMLP X X X X X X X X X X X X X
COIN X X X X     X   X X      
CONOPT 3 X X X X X X X X X X X X X
CPLEX 11.2 X X X X X X X X   X 10.0 9.1 8.1
DECIS X X X X X 32bit   X     X X X
DICOPT X X X X X X X X X X X X X
GUROBI 1.0 X X X X                  
KNITRO 5.2 X X X X X 32bit     X X      
LINDOGLOBAL 5.0 X X X X X X     X X      
LGO X X X X X X X   X X X X X
MILES X X X X X X X X X X X X X
MINOS X X X X X X X X X X X X X
MOSEK 5 X X X X X X X   X X 3.2    
MPSGE X X X X X X X X X X X X X
MSNLP X X X X X 32bit     X X X    
NLPEC X X X X X X X X X X X X X
OQNLP X 32bit X 32bit                  
OSL V3 X 32bit X 32bit X 32bit   X     V2 V2  
OSLSE X 32bit X 32bit X 32bit   X          
PATH X X X X X X X X X X X X X
SBB X X X X X X X X X X X X X
SNOPT X X X X X X X X X X X X X
XA X 32bit X X X 32bit   X     X   X
XPRESS 19.00 X 32bit X 32bit X 32bit   18.00     16.10    
1)GAMS distribution for HP 9000/HP-UX is 22.1.
2)GAMS distribution for SGI IRIX is 22.3.
3)GAMS distribution for DEC Alpha is 22.7.