one of the reasons that SIE instruction was so slow on the 3081 ... was that the service processor had to page some of the microcode in from 3310 FBA disk. things got faster on 3090 with SIE microcode resident ... and a lot more virtualization hardware support ... eventually expanded to PR/SM (on 3090 ... compete with amdahl hypervisor; basis for current LPAR ... effectively subset of virtual machine function).
misc. old email discussing 3081/3090 SIE issue/differences http://www.garlic.com/~lynn/2006j.html#email810630 in this post http://www.garlic.com/~lynn/2006j.html#27 virtual memory ... aka TROUT was code-name for 3090 ... presumably part of the implementation trade-off for the 3081 was that vmtool (internal high-end virtual machine & used sie) was purely planned on being used for mvx/xa development (and never planned on shipping as product). in that environment there was less of concern of production use of vmtool/sie and therefor less of performance issue (at least involving doing lots of switching between virtual machines and therefor SIE execution happened relatively infrequently). -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
