32 bit vs. 64 bit

If you must run 32-bit Web servers, follow these recommendations:

• Do not use the /3gb switch for 32-bit systems. If you are running 32-bit Web servers, we recommend that you do not use the /3gb switch in Windows Server 2003 to change the 2 gigabytes (GB) of virtual address space to 3 GB for all user mode processes. We recommend against using the /3gb switch because most SharePoint site traffic involves sending large amounts of data through the operating system. Therefore, leaving only 1 GB of address space for the operating system can destabilize the computer. For more information, see the following article in the Microsoft Knowledge Base: The Windows Server 2003 /3GB switch is not supported in Windows SharePoint Services 2.0 or in later versions or in SharePoint Portal Server 2003 SP2 or in later versions (http://go.microsoft.com/fwlink/?LinkId=105919&clcid=0x409).

• Mixing 32-bit and 64-bit servers can affect load balancing. You can run an environment that has some Web servers running the 32-bit version of Office SharePoint Server 2007 and others running the 64-bit version. However, there is a risk that the 32-bit Web servers may become overloaded if your network load balancer is configured to use a less-intelligent model as such round robin. We recommend that you configure your load balancer to manage distribution based on load.