Thread: Overclocking
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igor is offline igor
2007-07-13 , 11:59
Posts: 198 | Thanked: 273 times | Joined on Jan 2006 @ Helsinki, Finland
#9
Originally Posted by fanoush View Post

Thanks for clearing it up. So to sum it - over/underclocking n770 makes little sense because frequency scaling alone does not save much. Over/underclocking N800 make better sense because of possible voltage scaling (undervolting) when the clock runs slower.
However it might be that even on 770 something could be obtained. I'm just saying that the n800 HW has been specifically designed for doing it, while the 770 wasn't intended (but it might be possible).

Originally Posted by fanoush View Post
But still the CPU (i.e the ARM core) is only one piece of the puzzle and when it is not used much (like the internet radio case above or most other use cases) the savings are not substantial, correct?
The summary is that "it depends". So the total current (measured from the battery) is what must be optimised.

Originally Posted by fanoush View Post
Do I understand it correctly that when CPU is idle it is in some sleep state where voltage/frequency doesn't matter at all so the only savings gained by D(V)FS are when CPU is actually doing something (i.e executing code)?
Yes, in OMAP2 it is called retention (Deep sleep in OMAP1) and can be described as: sysclock stop, vcore lowered.
Last edited by igor; 2007-07-13 at 12:04.