I hate to ask the "simple" (possibly overlooked) question, but is it possible you moved from a configuration with 3 CPs to a configuration with 4 CPs but with more of a sub-capacity setting? That's certainly possible, at least on a System z10 BC.
For example, if you started with a 2098-D03 capacity configuration and moved to a C04, you would be moving from a configuration with a PCI (Processor Capacity Index) of 121 up to a PCI of 130 -- a greater than 7% increase. In other words, in the IBM Large Systems Performance Reference (LSPR) tables, you would be moving to a higher performance system, with greater throughput for typical measured LSPR workloads. However, the "uni" speed of each engine would be reduced, so you would expect to see somewhat elongated execution time for single threaded workloads relative to the previous configuration. So that's another thing to check: did you increase overall "MIPS" but decrease per-engine "MIPS"? On the z9 BC, z10 BC, and z114 models that's very easy to check: just look at the letter in the capacity setting. If the letter didn't change, then you should only see SMP effect. If the letter is lower (D to C, for example), then you probably are experiencing what I am describing. I suppose I should also ask the simple question of whether that additional CP is properly activated, defined, and actually available to your z/OS LPAR (s) for dispatch, but maybe that's been covered by now. :-) Keep in mind that z/OS Workload Manager (WLM) is boss, subject to capacity limits of course. If you have a job that's running longer, but it's still meeting or beating the WLM goal, then z/OS considers that perfectly fine because it's doing exactly what you told it to do. It could very well be that more overall work is getting done faster thanks to the additional engine, and WLM made the correct adjustments based on your settings. (For example, work that was getting deferred is now getting executed, and that particular work is putting some greater stress on the caches and/or on I/O.) If you aren't happy with the results, consider adjusting WLM settings. -------------------------------------------------------------------------------------------------------- Timothy Sipples Resident Enterprise Architect (Based in Singapore) E-Mail: timothy.sipp...@us.ibm.com ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
