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![]() HP OpenVMS Systemsask the wizard |
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The Question is: What performance differences would you expect from moving from Wide SCSI adapater to UltraSCSI adapters, using RA7000 on an OpenVMS V7.1 Alphaserver 8400 Cluster. The Answer is : The performance gain depends highly on what factor(s) are currently limiting the application performance... Without specific details on the current application activity and particularly the current application bottlenecks, the OpenVMS Wizard could expect anything from zero to very large gains to (rather unlikely, but still remotely possible) negative performance impact... If the application is not I/O bound, then there will be little or no gain. If the application is heavily I/O bound, then improvements in caching and increases physical memory may be appropriate. If caching is appropriate and sufficient physical memory is available, then the performance increase from the storage I/O changes will roughly parallel the differences between the controller and disk throughput for the subsystems. Obviously...
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