Cathy's techpaper:
IBM zEnterprise 196 and IBM zEnterprise 114 I/O and FICON Express8S Channel Performance (Cathy Cronin, Version 2, November 2011) (ZSW03196USEN01) http://public.dhe.ibm.com/common/ssi/ecm/en/zsw03196usen/ZSW03196USEN.PDF On Wed, Mar 7, 2012 at 12:49 PM, Ron Hawkins <[email protected]>wrote: > Radoslaw, > > Actually RMF does not report channel utilization for FICON. It is showing > you microprocessor busy on the host channel board. > > For the same MB/sec this metric will change depending on block size, data > length and whether zHPF is used. > > You can quite easily saturate a host channel MP with small blocksizes. I > haven't measured the 8S channels yet - we're just installing them - but I > think that with non-zHPF and 4KiB single blocks they would run out of steam > at around 200MB/sec (50K IOPS). I think Cathy Cronin has published a paper > with better numbers than my wild asses guess. > > Ron > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:[email protected]] On > > Behalf Of Mike Schwab > > Sent: Tuesday, March 06, 2012 1:23 PM > > To: [email protected] > > Subject: Re: [IBM-MAIN] FICON channel ulitization > > > > No. You are dealing with one device and no intermediate device to buffer > > the transmission rates. Transmission rate is negotiated to the fastest > rate > > that both ends support. > > > > Both ends are transmitting at that same rate, and are busy for the same > > amount of time. > > > > In contrast, say you were downloading over the internet through several > > devices. The source could send the file at full speed, but is buffered > by > a > > device in the middle. It is relaying the data at a slower rate over a > slower link > > to you. > > > > On Tue, Mar 6, 2012 at 3:12 PM, R.S. <[email protected]> > > wrote: > > > W dniu 2012-03-06 21:33, Mike Schwab pisze: > If the receiving switch > > > is 4G, that is the maximum transmission rate > from the 8G channel. > > > > It was busy 100% at 4G. I think I understand it now. So, chpid > > > connected to 8G sfp on the switch, then to 4G CU would show 50% > > > utilization? Radoslaw Skorupka Lodz, Poland > > -- > > Mike A Schwab, Springfield IL USA > > Where do Forest Rangers go to get away from it all? > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, send > email > to > > [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
