Windows 7: Turbo Boost

I'm using a DX58SO with an i920. In the BIOS, everything looking like Turbo Boost and Idle has been enabled to allow for full use of all these features. Yet, if in Windows I use the PerfMon and check C3 Transitions or C3 Time, I get zero. There's a tool called TMonitor which seems to tell me my CPUs (all 4) are running at around 1.6 GHz when idle. The CP frequency seems to increase when I do something, but there are still no C3 Times or Transitions. I'm wondering, is the Turbo Mode not working or is the system even continuously throttle down? Thanks for all comments in advance.

Are you using some type of stress test to make the system require more speed?

Good point. No - I'm just looking at the values while the system is more or less idle, then I start a browser or an email client, load a website, and then shut the applications down again.

Sometimes for brief moments the indicated CPU freq in the TMonitor tool shows 2800, and the CPU-Z v. 1.54 also shows this speed. So there probably is some moderate Turbo Boosting taking place.

However, why are there no C state transitions or times after I shut the applications down again, or when I start them up?