----- Original Message ----- From: "Edward Jaffe" <[EMAIL PROTECTED]> Newsgroups: bit.listserv.ibm-main To: <[email protected]> Sent: Friday, July 20, 2007 11:54 AM Subject: Re: PSI MIPS (was: Links to decent 'why the mainframe thrives' article)
> > I really wasn't paying any attention to this thread. But, I happened to > read the non sequitur you posted (see below), and thought I should respond. And I appreciate the information. I wasn't aware of it before, so all I had was the article's information about installed MIPs. I realize that this is not a true comparison, and I stated that - but it was all I had at the time. I'm happy that I did, as it seemingly encouraged you to provide a link to much better information. >> > First, you compare installed MIPS with performance. Nothing need be said > about that. Non sequitur. Then you asked what the highest performing > mainframe was in 2000 vs today. I believe I answered that question > correctly. I didn't say your information was wrong, just that it didn't address the original point. > > I'm not sure I follow your reasoning. Part of mainframe processing > "power" lies in its ability to do effectively use SMP (up to 54-ways now > ... more later). It's part of the equation. Good benchmarks are based on > computing throughput ... not individual chip speed. If you are comparing processors (which was the basis of the original question), then the compute speed of the chip *is* relevant. If you are comparing systems, then your benchmarks simply have to be testing the same thing (memory bandwidth/latency, I/O rate, transaction rate, etc.). Again - the question was "Why do people think that mainframe processors are slower?". . > > Read your own statement quoted up above. You originally said x86 had an > 8-fold increase over seven years. (Is that chip speed or actual server > speed?) Actually, I was rounding a bit. My original post on the subject indicated that the span for x86 comparisons was Nov 2000 thru June 2006 (as I was trying to use roughly the same period as in the post I was responding to at the time), and the increase was from 5.8 to 63.6, so the numbers should be a 7.95x increase in just over 5 1/2 years. > Now you're saying it had an 8-fold increase in just 4 1/2 years > -- the time frame over which the mainframe had a 6.6:1 processor speed > increase (or 2.5:1 individual CP speed increase if that's what you > choose to focus on). However you slice it, x86 processor performance has increased at roughly twice the rate as mainframe processor performance. I know that some here will take this as an insult, or a put down, or some attempt to make the mainframe look bad. It is, however, simply a reasonable conclusion based upon the available evidence. If someone has different data, please present it rather than just taking umbrage and arguing about little details that are not really important. If we want to talk fallacies, that's known as a Straw Man. > > I wasn't aware that people think mainframe processors are slow compared > to others. Is this from a survey of some kind? Or perhaps from that IT > Jungle article you referenced? Can you post the URL? I'm including below the full text of the original post by Steve Thompson that got me onto (into?) this whole thread: ---------------------------------------------------------------------------- ----------- -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Tim Hare Sent: Friday, July 13, 2007 1:52 PM To: [email protected] Subject: Links to decent 'why the mainframe thrives' article http://arstechnica.com/news.ars/post/20070711-legacy-matters-why-the-ibm -mainframe-continues-to-thrive.html referenced article http://www.itjungle.com/big/big071007-story01.html <SNIP> I keep seeing references to the "mainframe" processor is slower than those used in other platforms. Seriously, in an effort to compare processor power, IF one were to take a COBOL program that would process 1000 records from a data base and produce a report (let's say a payroll check register), which system would process this in the least amount of elapsed time? I ask this question in this fashion, because I know that Fujitsu has a COBOL compiler that produces code that runs under Windows (I know, because I have used it to do "batch" reporting at one time). I understand that a similar compiler is available for other of the platforms. So, if we run the data base and applications system on a self-contained system, which one will run with the lowest wall time? This is the kind of benchmark that needs to be done. It, in my opinion, is the only way to get close to a valid comparison. Anyone else have any ideas? [I still have the compiler, and I still have w/2K that I fixed it to operate with if anyone would like to try to build a benchmark.] Regards, Steve Thompson ---------------------------------------------------------------------- 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
