--- On Tue, 10/5/10, Edward Jaffe <edja...@phoenixsoftware.com> wrote:
From: Edward Jaffe <edja...@phoenixsoftware.com> Subject: Re: Maximum # of processors for Z/os To: IBM-MAIN@bama.ua.edu Date: Tuesday, October 5, 2010, 8:48 AM On 10/4/2010 11:57 AM, Ed Gould wrote: > A LONG time ago(20+ years I think) IBM did some studies on the maximum number > of Processors that MVS (at that time) could effectively use before there was > degraded throughput. My memory says is was 15 (I could be wrong). > Has Z/os changed that number, if so what is the current number before thruput > either is not helped or there is a straight line being nio help/no hurt ? > I am talking 1 copy of MVS on a CEC not mulriple copies. Bob Rogers gave a presentation about this (can't remember right now if it was at a TDM or at SHARE) right around the time they raised the number of logical CPs supported by z/OS to 64. It was interesting because the impact of having many logical CPs depends on the workload--with so-called "traditional" workloads faring somewhat worse than so-called "new" workloads. In any case, after studying this question IBM concluded that changes in hardware and operating system design have and will continue to reduce interlocks to the point where it makes sense for z/OS developers to invest valuable development resources supporting higher and higher numbers of logical CPs per image. The current limit is 80. Ed: That is terrific. Does anyone have the share presentation they can share with me or perhaps a manual # I can look for that talks about this some more? Thanks, Ed ---------------------------------------------------------------------- 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
