Bill, My memory, and follow up calculation, says that a 3390 rotated every 14.2ms, not 16.67ms.
Even so, it would hardly seem a good move to multiply or divide a metric based on transfer time by the avg latency of a disk drive. I don't see the relationship. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of > Bill Fairchild > Sent: Thursday, August 13, 2009 4:40 PM > To: [email protected] > Subject: Re: [IBM-MAIN] Degraded I/O performance in 1.10? > > It was probably a good value to use aeons ago when it took a real SLED 3390 > 16.67 ms. to spin around once, so 8.3 ms. was 1/2 revolution. Today, however, > is aeons later as far as the hardware is concerned, especially channel speed > when delivering data from controller cache instead of straight from the > platter. > > Bill Fairchild > > Software Developer > Rocket Software > 275 Grove Street * Newton, MA 02466-2272 * USA > Tel: +1.617.614.4503 * Mobile: +1.508.341.1715 > Email: [email protected] > Web: www.rocketsoftware.com > ---------------------------------------------------------------------- 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
