The Windows 2000 Server family is available in several different versions differentiated by the maximum number of CPUs supported, maximum memory supported, and other features:
Windows 2000 Advanced Server and Windows DataCenter Server include support for failover clustering and TCP/IP network load balancing that are lacking from Windows 2000 Server.
Similarly, SQL Server 2000 is available in two editions differentiated by the maximum number of CPUs supported, maximum memory supported, and other features:
In contrast, Host Integration Server 2000 is available in a single version that can be run on any of the Windows 2000 Server family products.
The choice of which version of Windows 2000 Server and SQL Server 2000 to install should be based on the anticipated work loads and the numbers of users to be supported. If failover clustering or network load balancing is desired, then Windows 2000 Advanced Server or Windows 2000 DataCenter Server will be required with SQL Server 2000 Enterprise Edition.
Since data movement tends to be an intensive input/output task, adding more CPUs may not provide the consequent increase in performance expected. It may make more sense to add additional network cards to separate network communication with the AS/400 host computer using Host Integration Server from local network access to the SQL Server by desktop computers.