Anyone remember "wait states" in the early IBM/clone 8088 PC's because of the slower memory chips?
Sent from Proton Mail mobile -------- Original Message -------- On Jul 15, 2023, 2:41 PM, Joel C. Ewing wrote: > The SU/sec advertised for those models indicates it is correct to call a 504 > cpu "slower" than a 701 cpu, even if that distinction is created at a level > above the physical hardware. If it is true that at the hardware level the > processor clock cycle is identical for all processors, then obviously that is > not the only determinant of the effective cpu execution speed. I would guess > that the capacity restrictions described force some desired percentage of > clock cycles to be idle/no-work cycles, reducing the effective execution > speed of the processor. That does seem like an ingenious approach for > allowing modest upgrade paths in an age where adding a full capacity cpu can > be way too large of an increment. JC Ewing On 7/15/23 05:43, P H wrote: > All > processing units (PUs), whether CPs zIIPs, SAPs, ICFs or IFLs have the SAME > cycle time (speed). It's the CAPACITY settings which are different. For > example, in case of the z16 the 701 is 100% then the relative capacity of a > 601 is approx 66% of the 701, 501 is approx 41% of the 701 and 401 is approx > 12% of the 701 > > Regards > > Parwez Hamid​ > > ________________________________ > From: IBM Mainframe Discussion List on > behalf of Jon Perryman > Sent: 15 July 2023 05:54 > To: > IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: A question about CPU usage on z/OS > > > While each cpu in the 504 is slower than a 701 cpu, running 4 batch jobs at > the same time should reduce run time because each batch job expect reduced > wait because there is reduced competition for the CPU. However, you could be > correct if the 4 batch jobs are experiencing heavy I/O wait. > On Friday, > July 14, 2023 at 06:05:24 PM PDT, Tom Brennan wrote: > > On 7/14/2023 3:01 > PM, Jon Perryman wrote: > > As for batch running slower at night after you > went from 1 CPU to 4, > that doesn't make sense unless other things changed. > > > I'm thinking it could be as simple as say, going from a 701 to a 504. > > The overall MIPS are bumped up, multi-task address spaces are happier, > but > single threaded work can be left in the dust. > > > ---------------------------------------------------------------------- > For > IBM-MAIN subscribe / signoff / archive access instructions, > send email to > lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > ---------------------------------------------------------------------- > For > IBM-MAIN subscribe / signoff / archive access instructions, > send email to > lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > > ---------------------------------------------------------------------- > For > IBM-MAIN subscribe / signoff / archive access instructions, > send email to > lists...@listserv.ua.edu with the message: INFO IBM-MAIN -- Joel C. Ewing > ---------------------------------------------------------------------- For > IBM-MAIN subscribe / signoff / archive access instructions, send email to > lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
