Apologies for missing this thread earlier. Please look at http://www.vm.ibm.com/perf/tips/z890.html
There was been a lot of confusion in this area, and I'm responsible for some of the confusion. To comment on a few of the side threads: - Do not hold breath for BASIC mode to return. In order to be cost effective in bringing things such as Logical channel sets, LPAR is required. Just one example. - The 80/20 rule for combating SIE breaks in the multi-level environments is I/O. Trading off memory for I/O is usually the best approach. There are other games one could play, but the return on investment usually doesn't pay off. - Even the new assists do not all apply to VM on VM on LPAR - A second level VM running as V=V on a VM in BASIC mode will take the vSIE hit as well. Bill Bitner - VM Performance Evaluation - IBM Endicott - 607-429-3286
