Ted MacNEIL wrote:
... Did you tell him about the IEFBR15 utility? ... IBM used to use one in the early days of bench-mark(ett)ing to get rid of the low utilisation effect.
<snip>
I'm not sure what that had to do with either benchmarking or marketing.
It's been a Long Time, but as I recall, sometime in MVS/XA Version 2 or MVS/ESA Version 3 the dispatcher was changed in such a way that it created an LUE. That is, at low utilization levels, the processor appeared to have less available capacity than it actually did. As a capacity planning aid, someone (WSC, if I remember right) suggested running one BR15 program per processor at a very low dispatching priority and in their own RPGN, to keep the machines 100% busy while providing a number that could be subtracted from the system's capacity to get the true utilization.
This effect got smaller as the machine got busier. Our capacity planning and performance measurement team, when queried, did not want us to run the BR15s because they only cared about peak time measurements, when they found the LUE insignificant for their purposes.
Corrections welcome...like I said, it's been a Long Time. -- John Eells z/OS Technical Marketing IBM Poughkeepsie [EMAIL PROTECTED] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
