Processor Power Management

[Agera One]

Okay. Someone explain the above three attribute.
1) min. processor state -- ? Processor turns off when battery reaches 5%
2) System cooling policy -- ? (no idea what will it is for and what it means for active/passive)
3) max. processor state -- ?

 

[SchizTech]

Great, thanks. Shouldn't I give the min. processor state a 1% value?

It probably wouldn't make a difference since the CPU isn't capable of that low a frequency in the first place. Technically it can't go as low as 5% in reality either.

 

[SchizTech]

1) The CPU doesn't shut off; the percentage refers to the lowest % of CPU frequency available. Modern CPUs have the ability downclock (run at a slower speed when idle) though they don't actually go as far down as 5% of their rated clock speed. If a CPU is rated 3.2 GHz, for example, it doesn't run at that speed all the time, to save power (battery life in a mobile device) when not needed. It may idle at 1.2 GHz (just a number off the top of my head, not referring to any particular chip)

2) The active/passive states refer to running the CPU fan. Passive doesn't mean the fan never spins but it runs less often.

3) The counterpoint to #1. Max CPU state means top speed (automatically 100%). Setting a lower percentage here lowers maximum performance but should save some power.

 

[Agera One]

Great, thanks. Shouldn't I give the min. processor state a 1% value?

 

[SchizTech]

Great, thanks. Shouldn't I give the min. processor state a 1% value?

It probably wouldn't make a difference since the CPU isn't capable of that low a frequency in the first place. Technically it can't go as low as 5% in reality either.

 

[Agera One]

So, do you know how low a CPU can go? Just to know..

 

[SchizTech]

It depends on the chip in question. Maybe a couple hundred megahertz. What percentage that comes do depends on the chip.