AMD Athlon64 cool'n quiet - questions

[Alexander Volovics]

The 'AMD Athlon64 qool'n quiet - how?' thread reminded me that there
are some questions that I would like to ask about 'cool/quiet',
'cpufreq/cpuspeed' and/or 'powernow-k8'.

(I am running FC3-x86_64 on a MSI K8N Neo2 Platinum mobo with AMD64 3500+).

'dmesg' shows the following:
powernow-k8: Found 1 AMD Athlon 64 / Opteron processors (version 1.00.09e)
powernow-k8:    0 : fid 0xe (2200 MHz), vid 0x2 (1500 mV)
powernow-k8:    1 : fid 0xc (2000 MHz), vid 0x6 (1400 mV)
powernow-k8:    2 : fid 0xa (1800 MHz), vid 0xa (1300 mV)
powernow-k8:    3 : fid 0x2 (1000 MHz), vid 0x12 (1100 mV)

However I have only ever seen 2 freqencies in use: 1000 and 2200.

This could because 1800/2000 are excluded from use somewhere or
because they are 'transient states', only used when switching from
1000 to 2200.

If 'cpuspeed' is responsible for this "exclusion" of 1800 and 2000
it doesn't seem to be configured in /etc/cpuspeed.conf.
(Or can the OPTS entry be used for this?)

Can somebody explain this phenomenon.

(I might not be seeing the actual workings of cpuspeed because
 I only use 'cat /proc/cpuinfo' manually)

Ubuntu Warty has a 'cpufreq' button for use on the panel.
Is there anything like this available for FC3/FC4?

Alexander