On Thu, 4 Feb 2010 08:19:18 -0600, Tom Marchant <m42tom-ibmm...@yahoo.com> wrote:
>On Wed, 3 Feb 2010 16:37:36 -0600, Mark Zelden wrote: >> >>I'm not trying to start an argument, but performance is not about "beliefs" >>or "gut feelings". It's about measurements and data / facts to back it up. > >I agree completely. > >> >> >>So I guess my point is, putting aside software costs, it is better from an >>overall system performance perspective to have all GPs. > >Again, is that "belief" or "measurement"? > Measurement. There is a measurable overhead in switching work over to a specialty processor. Patrick already quoted / linked to one source: http://www.itindepth.com/JoseCastano-zAAP.htm "... less than 5% - we usually see around 1-3% in lab measurements - a recent customer measured 2%" Frankly, I am a little surprised about the way this thread has gone. zAAPs and zIIPs weren't invented to improve performance. They were created for marketing and software pricing since that is a major issue with our platform. If all the engines and software were cheaper, the platform would be better off without them. (and yes, I'm still leaving out the caveat of full spead zAAPs/zIIPs on a knee-capped box - again, that is a marketing point to help sell them, to decrease software costs and encourage "new workloads"). Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America / Farmers Insurance Group - ZFUS G-ITO mailto:mark.zel...@zurichna.com z/OS Systems Programming expert at http://expertanswercenter.techtarget.com/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html ---------------------------------------------------------------------- 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
