[ubuntu-uk] pc frequency monitoring thing in taskbar

[Michael Wood]

Matthew Wild wrote:
>
>
> On 11/6/07, *STONE COLD* <javad_ayaz at hotmail.com 
> <mailto:javad_ayaz at hotmail.com>> wrote:
>
>     i guess i dont know what frequency scaling means then!i thought it
>     was somthing to do with cpu loads!
>
>
> The idea is that when the CPU is not being used (like when the PC is 
> idle) the CPU will run at a lower frequency, saving power. When you 
> open an application, or use the CPU in some other way, it will return 
> to full speed (and the applet will show 100%).
>
> The system monitor applet is probably the most useful on a desktop PC.
>
> Matthew.
>
>
Attempt to undo confusion:

(1) Processor Scaling = Changing the amount of capacity and therefore 
power a CPU has available to it.
 
(2) Processor Usage  = The amount of CPU power which is being USED by 
the system normally expressed as a percentage of the total available to it.

All CPU's which support scaling (almost all modern non budget ones do) 
have certain percentages that they
can scale to. e.g. My AMD Athlon 64 can scale to:

1Ghz which is equivalent to 45% of it's total capacity
1.8 Ghz which is equivalent to 82% of it's total capacity
2 Ghz which is equivalent to 91% of it's total capacity
2.2 Ghz which is equivalent to 100% of it's total capacity

Using cpu scaling (AMD's = Cool'n'Quiet, Intel's = SpeedStep) can save a 
lot of energy[1] and keep your processor from being hot and noisy

The CPU scaling applet isn't measuring anything. It is simply displaying 
the current setting of your CPU. It is perfectly accurate.

What you probably want is the applet called "System Monitor" which does 
what is described in definition (2) and not the (very catchily named) 
"CPU Frequency Scaling Monitor" which
does what is described in definition (1)

Hope that makes things clearer.

- Michael

[1] in my case around 30 watts 
http://www.michaelwood.me.uk/wordpress/2007/06/07/bringing-down-your-carbon-footprint/

-- 
/\/\ichael [ email at michaelwood.me.uk  ]
  \/\/ood  [ http://michaelwood.me.uk ]