On Sat, 2011-04-16 at 11:13 +0200, R.S. wrote: <snip> > Last, but not least: CPU granularity. > You cannot buy 5% CPU more, or 35%, or 41%. You can buy CP, not half of > it. Situation is much better for smaller machines - mix of n-WAY + > subcapacity levels gives you really good granularity. However neither > MSU, nor MIPS should be used for capacity planning beacuse YMMV (IBM words). > > So, rough estimations are quite OK here, especially that your business > growth estimates are also rough and are not proportional to CPU > consumtion. Not to mention unplanned, "small" enhancements... > >
A very good point. I would restate in terms of MSUs since that's what we are billed on. We currently run a z9BC Q02. Which is rated at 46 MSUs. So that's generally 23MSUs per CP. So if we need only 10 more MSUs, we must go to a Q03 (assuming it were possible). But that would result in a machine with 69 MSUs whereas we only want 56 MSUs. Luckily, we can get the 56 MSUs billing we want by using "Group Capacity". I would say that if it were not for MSU based billing, everybody would be happy with just getting a new CP and having the excess just sitting around. In this case, the upgrade cost would only be the cost of a CP. But with tiered software costs, adding a new CP has financial considerations beyond the cost to acquire and maintain the CP. Especially if you have software which does not support sub-capacity billing. I hate tiered pricing. It is the main ammunition being used to eliminate the z. Not the reason, the reason is the the PHBs just don't want to be bothered with a multiplatform environment. It is more difficult for them to manage and they must learn how to manage something other than Windows. God forbid they should need to learn something new. Or do something other than what the Microsoft rep tells them to do. Hum, reminds me of the "glory days" of the past when IBM ruled and management obeyed. "The more things change. The more they stay the same." -- John McKown Maranatha! <>< ---------------------------------------------------------------------- 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
