My first thought is data proximity to instructions. That is data being modified within the width of the processor I-cache.
The data modification will cause cache flush of the I-cache, and many processor cycles to re-establish the cache and various pipelines. This happened with SAS when the z/900 (?) processors came out. There should be a discussion in the archives about the SAS version of this issue. The solution is to move the data far enough away from the instructions so that the modification does not cause the cache to be flushed. HTH, <snip> Hello, We recently installed a Z196 and we have one COBOL DB2 program that is using twice the CPU time as before the new CPU. The program has not been recompiled and the data volume is the same. IBM has found nothing, yet. Strobe has not revealed any answers. All other programs use about 1/2 of the CPU time now. Any help would be greatly appreciated. </snip> ---------------------------------------------------------------------- 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
