On Sat, 2006-06-10 at 15:35 -0700, Gerhard Adam wrote: > >I disagree. > >I lose 12-15% of the engine when I add the second one and I lose > >another 15% (or more) for each engine thereafter, up to about 8 or 9 > >engines. Going from >a 308 to a 309 adds only about 300 MIPS when an > >engine is (nominally) 450 MIPS. > > > >That to me is more than "almost" not worth figuring. > >Unless you like losing 1/3 of an engine? > > What are you losing? It isn't as if these processors are off playing > solitaire. They're paying the cost of communication to allow more > simultaneous operations for YOUR workload.
You're preaching to the converted Adam - we all know this - even Ted ... ;-). IBM even have the numbers on the web at http://www-03.ibm.com/servers/eserver/zseries/srm/ I'm sure all capacity planning people must have problems selling this to their people. I got dragged into a (quite heavy) debate at one customer where an application team paid for an upgrade to a CEC for a particular (new) workload. They saw the MIPS charts, and wanted that many MIPS out of the complex for "their" LPARs. Except they had seen the uni number, and multiplied it by 2. And as it turned out they were turning on engines number 5 and 6. Didn't that get sticky !!!. Shane ... (P.S. Sam, Ted did say a third of an engine, not the box) ---------------------------------------------------------------------- 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
