High Idle CPU Clock Speed (May 2)

[Philtastic]

Hey guys, after posting some decent battery usage yesterday, I decided to watch my Task Manager (because this is how I get my kicks) and I discovered that my CPU was idling in the 0.9-1.1 GHz clock speed range which is a lot higher than the 0.5-0.7 GHz range I had a couple of months ago. This is with nothing explicitly running with no disk or network usage and with CPU usage < 2%. Intrigued, I decided to use the touchpad to switch Task Manager graphs when I saw the CPU clock speed instantly drop. Being surprised by this, I let go of the touchpad and saw my clock speed jump back up again. I repeated this a large number of times with a couple of system restarts and came to the conclusion that user input, whether that's the touchpad or holding down keyboard buttons or using the touch screen or stylus, was lowering my clock speed down to ideal idling levels.

I'm hoping that others can test this and confirm or deny this behaviour. If others are experiencing this, that means that Microsoft has royally screwed up the CPU clock speed control and we could all be having significantly better battery life. As of today, it seems that, to achieve optimal battery life, you need to constantly have user input going on to suppress the CPU clock speed.

 

[mrfroid]

Assumptions. Are you sure that your Surface running in 0.9-1.1 range is using more power than in 0.5-0.7? It looks like it shout it be so, but it's not. I checked how low battery usage goes when you increse/decrease minimum processor state from 5% and found that you can increase minimum up to 19% and you will still get same discharge rate (checked when idling of course). You even can't get anything around 0.5 when minimum processor state is 19%

 

[mrfroid]

sorry, my bad - at 19% it runs only 0.37