This used to be a big deal back in the 3090 (and prior) days. Less so now as the numbers sustain us to very high numbers of engines without much discomfort. In the original case (3 going to 4) I wanted (a few days ago) to point out the engine speed decrease was slight enough to probably not be the cause.
I might be wrong :-) but that's still my opinion... I know we've not really talked about MP ratios as a community for a very long time. I'm wondering what's been done in the past 15 years (other than multi-book machines since z990 and Hiperdispatch) to potentially change the picture. Anyone care to chip in? I'm also going to think about the effects of multibook and HD myself. On multibook I think it analogous to the old 280 and 380 models that were faster than the 200 and 300 models despite having the same number of engines (2 and 3 respectively) because of the second lot of cache. Cheers (as I just heard George Clooney say :-) ) Martin Martin Packer, Mainframe Performance Consultant, zChampion Worldwide Banking Center of Excellence, IBM +44-7802-245-584 email: [email protected] Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker From: Edward Jaffe <[email protected]> To: [email protected], Date: 12/02/2012 07:54 Subject: Re: Turning on additional CPs Sent by: IBM Mainframe Discussion List <[email protected]> On 2/9/2012 8:53 AM, Staller, Allan wrote: > There is a well know impact of additional CP's known as the "MP effect". > Going from 1 to 2 engines does not get you twice as much horsepower. > Only 1.9 times as much. > In the early days 360/65 AP& 305/65 MP, the effect was only 1.7 times. Specifically, if you look at z196 machines http://tech-news.com/publib/pl2817.html you'll see the following LSPR ratios: Modl Ratio Delta 701 2.15 N/A 702 4.06 1.91 703 5.92 1.86 704 7.72 1.80 705 9.47 1.75 706 11.17 1.70 707 12.82 1.65 and so on... -- Edward E Jaffe Phoenix Software International, Inc 831 Parkview Drive North El Segundo, CA 90245 310-338-0400 x318 [email protected] http://www.phoenixsoftware.com/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
