Hi Kevin,
thanks so much for following up. I had meanwhile found a similar document from Microsoft (probably an older version), and I have been experimenting with the settings to influence the transition through the P-States. The default settings seem to assume a totally idle CPU, that switches up as soon as e.g. an MP3 player is active in the background, or a website uses an annyoing flash advertisement. That naturally consumes more power and heat. The most important setting seems to be the "Processor Performance Increase Threshold", increasing it helps avoiding a switch up on minor CPU load peaks.
On my i5 the lowest state is 1.2 GHz. I wonder if it is possible to go below that, e.g. 1.0 GHz or 800 MHz, on very low CPU loads?
Cheers,
- ThunderBlade