Hello, Gerhard, Perhaps I wasn't completely clear, how about substituting the word "equivalent" for "equal"? Can you consider choosing now?
I used the concept of MIPS being about the same to be a short hand for the amount of measurable work done by the 3 CPU system is about the same as the 5 CPU system, MSUs, MIPS etc all are about the same number. If you had a pile of money to spend on one of two ROUGHLY equal boxes, one with 3 available CPUs and the other with 5, that being the only practical difference, which would you want, given the workload I described and the potential for some growth by adding fairly large workloads to the machine probably necessitating upgrades. Thanks, /ptd On Fri, Dec 19, 2008 at 5:47 PM, Gerhard Adam <[email protected]> wrote: > > > > If you had two machines, equal MIPS z10 BC boxes, would you want the box > > with 5 CPUs or the one with 3 CPUs? Memory, etc all equal. > > > > Well therein lies your problem. They are NOT equal machines and the reason > why this comparison is incorrect is because you're using that nonsense > metric MIPS. > > If we use your example and simply said that the total machine configuration > was 600 MIPS, then the one machine would actually be a 5 x 120 MIPS machine > and the other would be a 3 x 200 MIPS machine. They would be quite > different in the power available for any given set of instructions. > > This is only one reason why MIPS is such a bad number to use and is > generally so completely misunderstood. The most obvious point is that if > 600 MIPS were the power available, then it is clear that this is wrong since > no single unit of work could actually use it. > > Adam > > ---------------------------------------------------------------------- > 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 > ---------------------------------------------------------------------- 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
