Business Objects XI 3.1 is a 32-bit application and BI 4.x is a 64-bit applications.
BO XI 3.1 Web Intelligence is a 32 bit process. This means that a maximum of about 2GB of memory is available to the process. In XI 3.1, the Web Intelligence Processing Server (webi.exe application) could easily reach the 2GB maximum on a Windows OS. In BO XI 3.1, the recommendation was to scale the Webi out on a single node to utilize more than 2GB of the available RAM.
BI 4.0 is not limited to 2GB as the Web Intelligence server is a 64 bit application. 64-bit processes can utilize a lot more memory than 32-bit processes so this can greatly increase the throughput of a single process. In BI 4.x a single Web Intelligence Processing Server (WIPS) can utilize essentially all the available RAM on a machine in a single process.
BI 4.x upgraded with below features in 64-bit process.
• 64-bit Architecture.
• Native support for 64-bit Operating System for BI 4.0 server side components.
• Allows handling large reports: no more 2 GB memory limitation.
• 64-bit database middle-ware support.
• Java Application server utilizing 64-bit JDK’s (Java Development Kit).
• Desktop products and client tools support Windows 32-bit and 64-bit OS platforms.
The path to the 32 bit BI 4.x runtime will be:
C:\Program Files (x86)\SAP BusinessObjects\Crystal Reports for .NET Framework 4.0\Common\SAP BusinessObjects Enterprise XI 4.0\win32_x86
To the 64 bit runtime it will be:
C:\Program Files (x86)\SAP BusinessObjects\Crystal Reports for .NET Framework 4.0\Common\SAP BusinessObjects Enterprise XI 4.0\win64_x64
The Universe Design Tool needs 32-bit ODBC sources in order to create .UNV format universes. To do this, go via Start > Programs > Business Objects > BI Platform > “32-bit Data Source Administrator”. This version points to %WINDIR%\SysWOW64\odbcad32.exe
In BI 4.0, the WebI Processing Server and Information Design Tool need 64-bit ODBC sources for .UNX format universes. To do this, type ‘ODBC’ in Start > Run menu on Windows 2008 (64-bit) Server. This Data Source Administrator points to %WINDIR%\System32\odbcad32.exe
Any reports/Dashbaords/Crystal built on UNX universes, needs 64 bit ODBC drivers. Both 32 bit and 64 bit ODBC drivers need to be named same.
I have shared high level process and behavior of 32 bit and 64 bit process in business objects.If you really want to know depth knowledge of BO server processing, please get the SAP document here.