The following is an example of a large 32-bit application benefiting from the move to Windows Server 2003 x64 Edition. A multinational ASP.NET website on Microsoft.com was experiencing churning and restarting of the worker process running 32-bit Windows. Average worker process uptimes across the international portion of the application pool were less than an hour, and at peak times often got as low as every 5 minutes, which is clearly unacceptable. By moving the application to Windows Server 2003 x64 Edition, with no other changes to the application, the worker process was able to stay up comfortably for weeks at a time, eliminating the worker process recycling.
A key to the success for the Microsoft group was the ability to run its application in Windows on Windows 64 (WOW64) without any compatibility issues and with no required porting. They were able to simply plug in an x64 server and go.
Another group at Microsoft, using Windows Server 2003 and Microsoft SQL Server™ 2000 to run a large price-modeling application, was able to make a dramatic improvement in a key historical query by moving to x64. The application, which had been running on a dual processor, 32-bit, server was moved to a new 4-way, x64 server with 32 GB of RAM running Windows Server 2003 x64 Edition and a beta x64 version of SQL Server 2005. The historical query, which had taken 8 hours to finish on 32-bit Windows and SQL Server, now finishes in less than 5 minutes. The most important factor affecting the dramatic change was the increase in RAM and virtual memory address space.
An example of a workstation application that demonstrates the advantages of the additional memory and address space in x64 Windows is a customer who uses Computer-Aided Design (CAD) to design and model an engine. The fully rendered 3-D view is nearly 10 GB and takes more than an hour to load, but it can only be effectively worked on in a wire frame view. By moving to Windows XP Professional x64 Edition, the customer is able to load and work on the engine in a fully rendered view and see the results of changes in real-time.