Appendix B – Using Microsoft Windows Server 2003 x64 Editions
Microsoft offers a new generation of high-performance platforms for 64-bit applications with continued support for 32-bit applications and existing deployment and management tools – all on the same platform. These new operating systems provide an evolutionary path to 64-bit technology, allowing 64-bit and 32-bit applications to run side-by-side during the gradual migration to 64-bit computing.
64-bit editions of Windows Server 2003 running on Quad-Core AMD Opteron processors can improve the performance of HP SBC servers by processing more data per clock cycle, addressing more memory, and running some numerical calculations faster. Large data sets can be loaded entirely into memory, reducing the need for slower disk access; complex calculations that take hours to complete on a 32-bit system can be performed in minutes; and workloads that once required a large server farm can be performed by a single server.
In addition, this new 64-bit platform also removes many of the limitations that have previously inhibited scalability in an HP SBC environment.
Historical scalability limitations
32-bit Windows operating systems can directly address 4 GB of memory, 2 GB of which is reserved for the operating system kernel and 2 GB for applications. Since kernel memory is shared by all applications, the relatively small size of this space can be particularly problematic in an HP SBC environment where a server may be responsible for hundreds of users and thousands of processes. In this scenario, kernel memory can become constrained, making user response times unacceptably long and effectively limiting the ability of the server to scale up.
Historically, HP SBC environments have been implemented using 1P or 2P servers. Larger, more powerful servers have typically not been deployed for two main reasons:
•Kernel memory issues have limited the performance of more powerful servers; either a disk I/O bottleneck occurs or kernel memory is consumed before processor resources can be fully utilized
•Scalability in a 32-bit symmetric multi-processing (SMP) system is inherently non-linear above 2P
With these 1P and 2P server farms, opportunities to scale up are limited. As a result, customers are forced to scale out, which can create new problems such as deployment and management complexity, high power and cooling requirements, under-utilized resources, and minimal opportunities for server consolidation.
The 64-bit platform shatters the earlier 4 GB limitation – for example, Windows Server 2003 R2 Datacenter x64 Edition with Service Pack (SP) 1 supports up to 2 TB of RAM – effectively removing kernel memory limitations and eliminating disk I/O bottlenecks. By deploying a Windows Server x64 Edition operating system, customers can fully utilize the resources of their existing HP SBC servers and take full advantage of new, more powerful systems – whether they are running 32- or 64-bit applications.