Probably the overwhelming consideration is thread speed sensitivity. DDF probably OK with it, DBM1 Client SRBs likewise. Java batch jobs possibly not OK.
Cheers, Martin Martin Packer zChampion, Systems Investigator & Performance Troubleshooter, IBM +44-7802-245-584 email: martin_pac...@uk.ibm.com Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker Podcast Series (With Marna Walle): https://developer.ibm.com/tv/mpt/ or https://itunes.apple.com/gb/podcast/mainframe-performance-topics/id1127943573?mt=2 Youtube channel: https://www.youtube.com/channel/UCu_65HaYgksbF6Q8SQ4oOvA From: Carmen Vitullo <cvitu...@hughes.net> To: IBM-MAIN@LISTSERV.UA.EDU Date: 14/03/2019 15:24 Subject: Re: Effective of SMT with high zIIP usage Sent by: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> we tested with a single zIIP and turned it off quickly. We were eventually able to convert one spare CP to a second zIIP, and turned it on again on our secondary prod LPAR which was mostly all DB2 DDF type processing, both PROD1 and PROD2 were almost alway on the CAP, we saw some minor improvement, and are still studying the effects with SMT and without to see of the second zIIP helped us or SMT helped. the reason why is a CP3000 study was performed for us and the recommendation was to turn SMT off Carmen Vitullo ----- Original Message ----- From: "Bill Bishop (TMNA)" <bill.bis...@toyota.com> To: IBM-MAIN@LISTSERV.UA.EDU Sent: Thursday, March 14, 2019 10:08:36 AM Subject: Effective of SMT with high zIIP usage Anyone have any real-world experience with SMT? We have very high zIIP usage, 70% to 80% across 3 zIIPs, right now and have been asked to evaluate turning on SMT. One response was that with high zIIP usage, SMT might not be as effective as could be, and the other response is that it will make more efficient use of the zIIPS and allow them to drive higher. We are aware of the impact of zIIP overflow to CPs. Thanks Bill Bishop Consultant, Mainframe Engineer Mainframe and Scheduling | Infrastructure Technology Services Toyota Motor North America bill.bis...@toyota.com Office: (469) 292-5149 Cell: (502) 316-4386 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu 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 lists...@listserv.ua.edu with the message: INFO IBM-MAIN
