Back at my last employer when we were looking at setting a new server standard platform. I once got pulled into an all-day meeting with our IBM rep and a contingent of IBM sales guys from the Power division and another contingent of IBM Intel server guys. It was pretty comical listening to their conflicting sales pitches and the side conversations during the breaks where the IBM Power guys would bad-mouth the IBM Intel guys and vice versa when the others were out of the room.

I also had some interesting conversations with some of the Websphere product team at the IBM lab in Toronto where they told us "off the record" that we'd get better performance running Websphere Commerce Server on Linux vs AIX according to their internal tests and that they develop first for Linux and port to AIX.

I've always liked AIX and found the tools and overall experience very solid. It's just so darn expensive to scale and maintain it.

...or, making sure that the customer was aware of IBM's own published documentation, linked to in the paper, which explains the difference in how CPU utilization may be calculated by AIX vs. Linux on the same hardware.

You might wish to look at the paper describing how the PURR and SPURR components of recent POWER cpus assist with process accounting.

I understand that there's going to be some inevitable Lintel chauvinism on HN, insofar as it's the most popular platform...but there may truly be other legitimate ways of doing things.