> Well my question then is, what is a > transaction? A very good question, and exactly why the "how many PCs can I consolidate?" question is basically a useless one. The answer has to include what the PCs are doing and how they do it. It's comparing apples and pumpkins.
> So what is a transaction? The best definition I've come up with is a seqence of operations that accomplishes a single unique unit of business typical to an application, defined by the type of problem and type of application. > Would I want to > run 100 systems in a given z/VM each with some number of JVMs, yes > WebSphere? What do the applications running in the JVMs do? 8-) > On the topic of availability I am not sure I buy the whole MF > is better > than 80x86 or Intel / AMD 64 server hardware. Today, everything is > redundant and everything is hot swapable. But not to the point of being able to intercept failed instructions and re-dispatch on pre-installed spare hardware, unless you've bought a really Tandem or some such system, at which point you're not paying much less than the equivalent zSeries. Correcting failure in flight isn't yet possible in Intel hardware systems, and even with the Opteron and Itanium, it won't be easy. None of the Intel systems share instruction pipelines yet. Now if some of the rumors about using a PowerPC core for the next gen zSeries processors are true, or that IBM licenses some of the PowerPC or zSeries multicore fab technology to AMD or Intel to make MCM-style platters of Intel engines, that might change the picture drastically. I don't see that happening, but it'd be a very interesting change in the landscape. > What is different > is to get a > new stick or replacement stick of memory for the MF could cost you and > automobile and you won't find that stick of memory at the > local computer > store. No, you'll find your IBM CE showing up at your door with the correct replacement in his hand before you even know it failed...8-) -- db
