I took for granted that the original writer means a 29% reduction FOR THAT PARTICULAR DATASET, not overall CPU usage. Maybe I was mistaken.
--- Bob Bridges, robhbrid...@gmail.com, cell 336 382-7313 /* If you suck at playing the trumpet, that's probably why. */ -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Robert Prins Sent: Sunday, January 19, 2025 10:07 <quote> 2 weeks ago I received the analysis data from a new client that wanted to reduce their CPU consumption and improve their performance. They sent me the statistical data from their z16 10 LPARS. Information about 89,000+ files. I analyzed their data and found 2,000+ files *that could be improved* and would save CPU when improved. *I pulled out 1 file to demonstrate a Proof of Concept (POC) for the client. I had the client run the POC and it showed a 29% reduction in CPU every time that file will be used. The 29% did not include 3 other major adjustments that would save an addition 14% CPU and cut the I/O by 75%.* This is just 1 file. The other files can save 3% to 52% of their CPU every time they are used in BATCH or ONLINE. </quote> I've been a programmer on IBM since 1985, and the above doesn't make any sense to me, how can changing just one file result in a 43% reduction in CPU usage? I've only ever been using PL/I, and using that I did manage to make some improvements to code, including reducing the CPU usage of a CRC routine by an even larger amount, 99.7% (Yes, ninety-nine-point-seven percent), but that was because the old V2.3.0 PL/I Optimizing compiler was absolute shite at handling unaligned bit-strings, but WTH can you change about a file to get the above reduction in CPU? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
