athlon64 cool&quiet / powernow-k8

[Satish Balay]

On Sat, 17 Apr 2004, Gene C. wrote:
> 
> I was not aware of this capability so I did some googling and looking at the 
> kernel source.  I have an Opteron 140 running on an ASUS SK8V mobo so ... but 
> then i find:
> 
> 1. Not enabled for x86_64
> 2. I cannot find any type of powernow-k8 driver module for configuration 
> option.
> 3. The utilities that I expect might be useful for this are in kernel-utils 
> for i386 are not in kernel-utils for x86_64.
> 
> This powernow stuff is a bit new to me so I just might be missing something.  
> Is there some doc of somekind that says what oit is suppose to do? The only 
> thing I can find so far is the kernel source and it is a bit cryptic for me.

The official name is 'AMD Cool&Quiet'. Try googling for 'Athlon64
Cool&Quiet'. This is supported on Athlon64 only - (i.e no support for
AthlonFX, Opteron chips)

I think this is similar to speedstep in intel mobile chips - and
powernow in mobile athlon chips. Basically the CPU supports The max
freq (for max performance) - and a few lower frequencies - which can
be used to save power.

Check out:

http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf

Satish