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GAMS is available in a 32 bit and a 64 bit version for Windows. The 64 bit version requires the presence of a 64 bit version of Windows to operate properly - just having a 64 bit processor is not sufficient. The 32 bit version of GAMS will work on both versions of Windows, but the operating system limits the GAMS process to ~ 1.7 GB (Windows 32 Bit) or ~ 4 GB (Windows 64 Bit).
In general, you should not expect a performance improvement from the 64 bit version. The benefit will be in being able to solve larger models. Please note that the 64bit version of GAMS may require up to 35% more RAM than the 32 bit version. Sometimes it may be advantageously to run the 32 bit version of GAMS on a 64 bit version of the operating system.
If you are not sure, which version of the operating system is installed on your machine, click on:
The command line tool
systeminfo, which is included in XP and more recent versions of Windows, provides an exhaustive snapshot about important system parameter. Below is an example outout:
Microsoft Windows [Version 5.2.3790] (C) Copyright 1985-2003 Microsoft Corp. X:\temp>systeminfo Host Name: XYZ OS Name: Microsoft(R) Windows(R) Server 2003, Standard Edition OS Version: 5.2.3790 Service Pack 2 Build 3790 OS Manufacturer: Microsoft Corporation OS Configuration: Member Server OS Build Type: Uniprocessor Free Registered Owner: XYZ Registered Organization: GAMS Development Corp. Product ID: 69712-XXX-YYYYYYY-ZZZ Original Install Date: 7/6/2006, 12:44:48 PM System Up Time: N/A System Manufacturer: Microsoft Corporation System Model: Virtual Machine System Type: X86-based PC Processor(s): 1 Processor(s) Installed. : x86 Family 15 Model 33 Stepping 2 AuthenticAMD~1994 Mhz BIOS Version: A M I - 9000520 Windows Directory: C:\WINDOWS System Directory: C:\WINDOWS\system32 Boot Device: \Device\HarddiskVolume1 System Locale: en-us;English (United States) Input Locale: en-us;English (United States) Time Zone: (GMT-05:00) Eastern Time (US & Canada) Total Physical Memory: 1,023 MB Available Physical Memory: 700 MB Page File: Max Size: 2,473 MB Page File: Available: 2,202 MB Page File: In Use: 271 MB ...