Windows Server 2003, Enterprise Edition fills many of the same roles as Standard Edition and adds features primarily geared toward improving reliability and scalability. Enterprise Edition supports a maximum of eight processors, which is double Standard Edition’s capability. Enterprise Edition also supports Address Windows Extensions (AWE), providing an extra gigabyte of memory to applications by reserving only 1GB for Windows, rather than Standard Edition’s 2GB/2GB split between the operating system and applications.

Enterprise Edition also supports Windows Clustering, allowing you to build failover clusters with two nodes. The Cluster Service allows you to create clustered file shares and clustered printers and supports clustered applications, such as SQL Server Enterprise Edition and Exchange Server Enterprise Edition. The Cluster Service even enables you to cluster applications that aren’t specifically designed for clustering, provided they meet certain criteria spelled out in the Windows online documentation.

Enterprise Edition can also host Microsoft Metadirectory Services (MMS), allowing large organizations to integrate multiple heterogeneous directories.Enterprise Edition ups the ante for scalability and reliability, as well. Enterprise Edition is available in a 64-bit edition for Intel’s Itanium family of 64-bit processors. With the proper server hardware support, Enterprise Edition also supports hot-add memory, which is the capability to add server memory while the server is running, and non-uniform memory access (NUMA). NUMA is a fairly new concept in the Windows world and occurs only in servers that are built with multiple separate processor busses. Each bus has its own memory, which is accessible at very high speeds to processors on that bus. When processors must access memory on other busses, however, access is slower. This disparity between memory access times is referred to as NUMA. High-end servers will be built with this multiple-bus architecture to provide faster memory access times.

Finally, Enterprise Edition supports the Terminal Server Session Directory, which makes working with large Terminal Services server farms more intuitive for users.

Enterprise Edition is an ideal platform for high-demand, mission-critical applications, including

• Mission-critical shared files

• Mission-critical printer access

• High-demand or mission-critical applications such as SQL Server or Exchange Server

• Any applications that can benefit from the 3GB memory space supported by Enterprise Edition