Adaptive vs Low

Hi to all,

i am using Lenovo's Power Manager on my T61 and i have set (and use) a custom power plan.

I saw that i had set "Maximu CPU Speed" to "Adaptive", when on battery. This means that the processors will be full throttle when there is actually the need to do so.
I experimented a little by setting this to "Low". The computer feels more slow indeed in that setting (does anybody knows how much done the processor will go on this ?)

Has anyone seen any real battery difference between Low and Adaptive ?

 

To some degree what you are doing will make a difference. If you're doing non CPU intensive stuff, then it will probably not be a big difference, but if you're coding audio all day, then it will. I usually set the CPU to the lowest because the things I do like Office, Internet, Music, etc., aren't too hard on the CPU.

 

i've played with these settings for a few minutes too.
noticed that highest brings ur CPU + vCore to the stock speed + highest vCore
Adaptive fluctuates between the above setting & 6 x fsb + 1 step down vCore
Low locks your cpu @ the 6 x fsb + 1 step down from highest vCore
Lowest showed the same speeds above with CPU-Z 1.48 so i dont know what the difference is...

 

Thanks for the replies!

I use Visual Studio so i feel that "Adaptive" setting may be more right for me. I just do not know how much difference it will make to the battery.
I received today a 9 cell one, so i will leave it to Adaptive and stop worrying.

Thanks again!

 

If your applications behave properly, adaptive is the way to go. This will allow your processor to speed up for your requests to process them faster. If your applications stop making requests when they are no longer needed, your processor can immediately drop back down to a slow speed. This gives you the combination of good battery life and good responsiveness. I would also recommend using adaptive when plugged in because you get great performance and can keep down heat/noise compared to maximum (I even use this setting on my desktop computer).

The problem with adaptive is misbehaving applications. If one of your apps requests more power than it needs, or it gets stuck in a loop (Firefox on a bad page is notorious for this), your processor may get stuck at the high setting. This will substantially reduce battery life while giving you little to no gain in performance. For this reason, I often run at slow while on battery just to keep misbehaving applications in check.

 

Ok, have you experienced any significant battery-save when on "Slow" (you meant Low ?) instead of "Adaptive" ?

 

It depends on your applications. If they only request max processor very short bursts, you will save very little by selecting 'Low' (maybe 15 minutes more on a 6 hour stint). However, if they thrash your processor and request way too much (Firefox on a bad tab, any Game, etc.), then you will see substantial battery savings (1 hour plus difference).

 

Vista advanced power settings has options for CPU
Lowest is 5%-33%
Adaptive is 5%-100%

Dunno about the fsb, but a post above specs 6x on adaptive, and I know it is also 6x for lowest

 

It's trivial to run a performance monitor in the systray so you can see if the CPU is pegged at 100%. Task Manager can do this (just minimize the main window) but Process Explorer is better because it can be configured not to take up a minimized programs slot on the taskbar.

 

That is certainly true. But sometimes I have Firefox open with 30+ tabs and it maxes out the thread. I know it doesn't need that much performance, and that it is the guilty party, but restarting it can be bothersome (would have to reload all the tabs, may need to log back in to various sites). A slow processor setting keeps this in check and maintains good battery life.

Again this is a specific reason. If you are able to keep your applications behaving properly and are dissatisfied with the performance of your computer adaptive is a good choice as it will provide a good balance.