Minimum Processor State

[Kaldari]

I understand the point of a "maximum processor state." You can lower it to restrict the CPU and gain battery life. The CPU consumes less energy and the fans consume less energy from a cooler thermal load.

I've never really understood the need for a "minimum processor state" though or what it even does for that matter.

Anyone?

 

[usasma]

Say that you're doing something long and intense with the system - and want to leave the computer but continue to process it at a reasonable speed.

Then the power settings won't lower the state below that specified level - so you can keep processing at a certain level even with the power settings turned on.

 

[Kaldari]

From what I understand, the clock speed is dynamic based on demand if the minimum and maximum aren't the same.

I might be stating the obvious, but doesn't that mean whatever is being calculated will actively cause the CPU clock speed to ramp up should the needs of the application surpass the minimum processor state?

I'm just not seeing the advantage of setting a minimum state above 5% (because it can't be set to zero. Just the computer running requires small amounts of CPU usage). If an application needs more processing power, the CPU dynamically ramps up to fill the needs of that application up to whatever the maximum state is. If the application no longer needs that heightened clock speed, why not let it conserve that power it's pretty much wasting?

I might not be seeing the full picture or something. I dunno.

 

[usasma]

We're a bit out of my depth here, so a lot of my "suspicions" are just guess-work.

What I suspect is that this is a power saving option - not a means for controlling processes. And the CPU, in order to save power, is automatically adjusted between 5% and 100% by the power saving system - depending on the needs of the system.

So, if the system is doing nothing, at some point the power saving stuff will decide to throttle the CPU back in order to save power.

I look at it sorta like a laptop running on battery power - it's slower and the screen is dimmer until you plug it in - then it speeds up because it switches to the AC mode power settings rather than the battery mode power settings.

 

[Kaldari]

That's precisely my view.

That was just my response to you saying one might want to increase the minimum if you're ever doing something CPU intensive while away from the computer.

I did do a bit more digging yesterday though. I read somewhere that some people have had a perceptible delay in the throttling up of the CPU when coming from the lower power state after they started to use the computer again.

So I guess someone may want to increase the minimum if they notice sluggish behavior after the computer's been sitting idle a bit.