On Wednesday, 05/17/2006 at 12:42 AST, John Campbell/Tampa/[EMAIL PROTECTED] wrote: > #1: A mainframe is designed to provide maximum *reliable* single-thread > performance (per CP) simply because a lot of the business workload (merge > phase of sortation, for instance, or balancing a b-tree after an insert) > needs it and errors can't be tolerated.
And yet I've seen graphs showing how z is optimitized for multiple-workload (thread) performance because of its low-cost context switching. That's why our memory and cache designs are the way they are, and why we can run multiple applications *well* on a single CPU. > #2: A mainframe provides maximum I/O connectivity. Granted, as we move > towards fibre channels we're getting away from this differentiator. I wish > I had a Shark ESS to play with... But there's still the sheer volume of connectivity: The old z9-109 allowed up to 84 4-port FICON Express2 cards for a total of 336 FC ports. (Truth in advertising: OSAs, ESCON, FICON, and Crypto cards all compete for those 84 I/O slots.) Alan Altmark z/VM Development IBM Endicott ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
