Many workloads exhibit a linear relationship between CPU utilization and throughput up through 100% CPU busy. Some do not. Workloads exhibiting these characteristics are not unique to any operating system or hardware platform. Mainframers are used to cramming disparate workloads into a single box and making them get along. *ix and desktop folk seem to "just buy another box to put the new workload in".
Developers of "desktop" workloads tend to code their applications from the perspective of a single user and not consider the consequences of several (or several hundred, or several thousand - or more) concurrent users. In my long and checkered career (sic), I had the opportunity to design and build an application for a single user, re-engineer the application to support several concurrent users, and re-engineer the same application again to handle several hundred users. It was "most educational" (cliches interpreted: the wounds are mostly healed over, the pain is now tolerable and the scars "add character") "Different strokes for different folks" (Sylvester "Sly" Stone) I'm a performace quant. I view the above as "opportunity for continued employment". Tom -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- This is a PRIVATE message. If you are not the intended recipient, please delete without copying and kindly advise us by e-mail of the mistake in delivery. NOTE: Regardless of content, this e-mail shall not operate to bind CSC to any order or other contract unless pursuant to explicit written agreement or government initiative expressly permitting the use of e-mail for such purpose. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Shane <[EMAIL PROTECTED]> Sent by: IBM Mainframe Discussion List <[email protected]> 04/10/2007 05:04 AM Please respond to IBM Mainframe Discussion List <[email protected]> To [email protected] cc Subject Re: IBM to the PCM market On Mon, 2007-04-09 at 23:52 -0600, Paul Gilmartin wrote: > > > > Not really. Since the *ix boxes max out at 30% utilization, you need > > > This statement has been repeated so often among mainframe > partisans that it has come to be accepted without question. > Can someone provide a source, attribution, citation, whatever? > ... > Inquiring minds want to know. Yes, minds - plural. I had toyed with making a similar post. I've no Unix background, merely Linux, but I'd be hard pressed to believe this RoT (if it is such) is valid. With respect to Linux, maybe it came from 2.4 kernel days - *lots* of servers still appear to run this for "stability". Maybe it came from 2.2. With 2.6 I'd be *real* surprised if you can't productively run the CPU much harder - although I/O (including swap/page) traffic can be a bit problematic at high rates. And of course there are next to no useful performance/tuning metrics. A real blindspot for some-one coming from RMF (yes, I've had a look at rmfpms). Shane ... ---------------------------------------------------------------------- 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
