On Wed, 21 Jul 2004 17:43:48 -0400, Cheryl Watson Walker <[EMAIL PROTECTED]> wrote:
>This is from our March 1991 TUNING Letter and our April 2004 CPU Charts, and >should provide everything you need: > >1 base CPU service unit = 1 TCB second * CPU-factor >1 base SRB service unit = 1 SRB second * CPU-factor >1 base I/O service unit = 1 EXCP or JES2 read or write >1 base MSO (main storage occupancy) service unit = ((number of frames of >central storage) / 50) * (base CPU service units) > >** CPU-factor defined by vendor; as an example, the CPU-factor for the >2084-310 (10-way) is 17003.1881 service units per second. Originally, one >service unit was supposed to represent 10,000 instructions. > >CPU service units = (CPU SDC) * (base CPU su) >SRB service units = (SRB SDC) * (base SRB su) >IOC service units = (IOC SDC) * (base I/O su) >MSO service units = (MSO SDC) * (base MSO su) > > ** SDC = Service Definition Coefficient, as defined by customer > > Total service units = CPU service units + SRB service units + IOC service >units + MSO service units > > Hardware MSUs for a machine = (CPU-factor * number-of-CPs * 3600- seconds) / >1,000,000 (rounded to nearest integer). The 3600 is to create a total for >an hour (3600 seconds) and the division by a million is to obtain the >millions of service units value. This calculation used to exactly match the >published MSU values, but now only comes close for the latest zSeries >machines. For the 2084-310 above, the service units would produce an MSU of >612 from the calculation; but initial hardware MSUs are 601 and published >software MSUs are 538. Notice that this is unrelated to TCB and SRB time. > > Software MSUs for a machine = about 10% less than hardware MSUs, but >determined by marketing. > > Application MSUs for an hour = (base CPU service units plus base SRB >service units accumulated for an hour) / 1,000,000. > >Hope that helps. > > Cheryl > Hello Cheryl; Do you know why the MSU calculation for the z990s (and I suppose for the new z9-109) does not match exactly as it was for the older machines?. I'm dealing with a Capacity Planning product that reports utilization in MIPS and I'm trying to get the vendor of such product to provide MSUs values as well. Maybe it does not make any sense as per the perpetual controversy regarding MIPS, but I want at least to have something adapted to the "new" paradigm for capacity. BTW, could you provide a "short" comparision and/or difference between MIPS and MSUs, if such is possible?. Kind regards, Giovanni ---------------------------------------------------------------------- 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
