SAP with Microsoft SQL Server 2005: Best Practices for High Availability, Maximum Performance, and Scalability70
64-bit memory and CPU limitations
The general memory limitations both for the 32-bit and 64-bit computing platforms are shown in the following table.
General Memory Limits
Total virtual address space
Virtual address space per 32-bit process
2 GB (3 GB if the system is booted with the /3gb switch) 4 GB if compiled with /LARGEADDRESSAWARE 2 GB otherwise
Virtual address space per 64-bit process
The physical memory and CPU limitations for the 32-bit and 64-bit Windows operating systems are shown in the following table.
Physical Memory and CPU Limits11
Windows Server 2003 Standard Edition
4 GB/1 to 4 CPUs
32 GB/1 to 4 CPUs
Windows Server 2003 Enterprise Edition
64 GB/1 to 8 CPUs
1 terabyte/1 to 8 CPUs
Windows Server 2003 Datacenter Edition
64 GB/1 to 32 CPUs
1 terabyte/1 to 64 CPUs
Migration to SQL Server 2005 (64-bit)
Despite the fact that the binaries of the IA64 and x64 platforms and the 32-bit platform are not fully interchangeable, the SQL Server 2005 on-disk structures between all three supported platforms (IA64, x64 and x86) are the same. This means that migrating from a 32-bit computing platform to one of the 64-bit platforms can be handled easily either by copying the database files to the new 64-bit hardware or by restoring a backup from the 32-bit platform to the 64-bit platform.
11 Product lists are for reference only. The lists do not represent final or actual product names or convey equal functionality between the 32-bit and 64-bit versions of Windows.
Microsoft Corporation © 2005