Power setting while plugged in

[rdh]

Hi,

From searching through the forum I see that some people set their AC power setting for their CPU to Maximum, and some set it to Adaptive.

1. If the CPU is set to maximum when using AC power, after a period of time does this increase chances of thermal or heat problems shortening the life of the thinkpad?


2. If the CPU is set to adaptive when using AC power, will it provide enough power or speed when needed to run more resource-intensive applications (DVD movies, games like Sid Meier's Pirates, Civilization 4 and MS Flight Sim)?


I've always used maximum setting on my T42p when it's plugged in but I don't want to damage the machine.

Thanks!

[EOMtp]

Intel has become so adept at dynamically throttling the Pentium M processors that one can hardly measure any performance difference between constant max CPU speed and dynamically throttled CPU speed.

Conclusion: One will neither know nor see any measurable difference in performance running the machine in "adaptive" mode all the time, regardless of AC or battery power.

The power consumption will be significantly lower in "adaptive" mode and the power dissipation (i.e., heat buildup) will be correspondingly lower. There is no reason whatsoever to run the machine in "max" mode.

[christopher_wolf]

Intel has become so adept at dynamically throttling the Pentium M processors that one can hardly measure any performance difference between constant max CPU speed and dynamically throttled CPU speed.

Conclusion: One will neither know nor see any measurable difference in performance running the machine in "adaptive" mode all the time, regardless of AC or battery power.

The power consumption will be significantly lower in "adaptive" mode and the power dissipation (i.e., heat buildup) will be correspondingly lower. There is no reason whatsoever to run the machine in "max" mode.

The only reasons I can think of for somebody to run in the Maximum clock setting is to make sure that they are getting all the clock all the time and squeeze out just a little more "juice;" in terms of the ratio of benefit/power consumed, you don't get much more than you already had. Intel has made the lag time from an idle clock setting to full (a slew rate of sorts) very small, small enough that for 99% of operations you would not be able to notice that it took a few cycles to go from 800MHz to full speed.

[rdh]

Thanks for the informative responses, EOMtp and Christopher. I'm going to change my AC power setting for CPU to Adaptive.

[jdhurst]

I can tell you that my T41 runs cooler on the ThinkPad setting than on Max Power. I used to run on Max until I read and understood some of the highly useful posts in here. I reset to ThinkPad default and the machine started running cooler immediately. Whenever it needs power it jumps straight from 600MHz to 1.8GHz.
... JD Hurst

[davidspalding]

I have profiles (customized) that do both ADaptive for AC & battery ("Adaptive"), and Adaptive or low for battery, and Max for AC ("David Power Source Optimized").

I don't notice big heat problems when it's plugged in with max CPU (as regular readers are probably loathe to hear again, I use a Targus Coolpad Traveler underneath,which significantly reduces heat buildup), but I DO notice the fan is quieter, and cycles less, on my "adaptive" profile.

Since my use of brute multimedia monsters is < 10% of my day to day computing, I don't need my "Power source optimized" profile much. It's nicer to have a quieter and infinitesimally slower response curve than Super Computer.

Gaming is a whole different story,though....