I'm not familiar with any variability issues that may arise out of running under z/VM but I would guess that guest systems might find more CPU variability than when running just under PR/SM. But that's just a guess.
My experience has been that when we moved from z900 to z9s we saw an increase in CPU time variation. When we moved from z9s to z10s we saw a larger increase in that variation. I believe the reason for this is the increased sensitivity to processor cache misses. (E.G. memory speed is not keeping up with CPU speed.) I've seen 10% variations on my z10s, but primarily when they're more heavily loaded. At some point I'd like to do a bit of studying on that and attempt to correlate the variation back to the numbers from HIS, but I haven't done that yet. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
