Hitachi 9960, 9900 Series manual Performance Considerations, Truly Scalable Performance

Performance Considerations

Truly Scalable Performance

Based on the internal switched-fabric Hi-Star™architecture, the Lightning 9960™ shows unmatched performance scalability. The more capacity and connectivity added to the 9960, the more total bandwidth increases. As stated previously, the 6.4GB/sec internal bandwidth is reached when all 16 modules are installed and functioning.

When new application workloads are added to a 9960 system with an existing workload, neither the new nor the existing workloads will suffer performance degradations from the sharing of internal resources and bandwidth. The following series of tests proves this point. By measuring the effects of one workload on another by only sharing the controller, we can illustrate this phenomenon.

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The more capacity and connectivity added to a Lightning 9900™ Series system, the more total internal bandwidth increases.

The Advantages of the Lightning 9900™ Series Hi-Star™Architecture Over a Shared Bus Architecture

A test was conducted that clearly demonstrates that the 9960 is not susceptible to performance declines typical of a shared bus architecture. The test compares an OLTP and a DSS workload running on both a Lightning 9960™ and a 7700E system. We use the 7700E as an example of the shared bus storage system architecture. In both cases, the same OLTP application workload was run on an HP/9000-K460®server and the same DSS workload was run on two Sun E3000® dual-processor systems. In one case, both processors were connected to a 7700E and then to a 9960 system4. There were no differences, therefore, from the application software or the server platform variables. They were the same for both sets of data. The only difference was the storage system in order to illustrate the advantages of the Hi-Star™switched-fabric architecture. Experimental results are shown in Figure 23.

Shared bus architectures are susceptible to performance bottlenecks.

Figure 23 –Test results show the advantages of the 9960 Hi-Star™architecture when compared to a shared bus architecture.

4See Appendix A for configuration details.

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