A few XP Registry Settings that help improve batterylife.

Under KEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager

Create a new key called Throttle. (If you've applied the tweak for dual core you'll already have the Throttle key.

Inside the Throttle key add these dword decimal values:

PerfIncreasePercentModifier - 70. This tells the OS at which load level to up the P-state to a higher one. Default is 20 which IMHO is a bit low. MS went save to avoid hiccups, but today with the CD or C2D it's powerful enough and has enough cache to avoid hiccups.

PerfDecreaseMinimumTime - 150000 (150ms) this tells the OS how much time to stay in the current P-State after hitting the drop down percentage before it can drop back down. Default is 500ms. Why state in any P-State longer than you have to? Even if it is half a second.

I got these from a Whitesheet. You may Google "Windows Native Processor Performance Control" and it'll bring it up.

You can play with the values but I've tested these and they help keep power usage down with out affecting performance noticably.

 

What are the estimated improvements in battery runtime?

 

It's hard to say. It doesn't improve your laptop on maximum power save settings. But these settings help close the gap between adaptive and power save settings.

Say you get 2:00 hours watch a DVD you might get a 10% improvement.

This also makes better use of Speedstep because it now gives the CPU a chance to use the intermediate speeds where before with a low 20% setting it'll most likely go from 1ghz to max ghz.

 

Cool.

Also if you are using NHC you have the ability to tweak these settings on the fly and have different settings for on AC or Batt.

 

Will this affect performance at all?

 

I think there is no correlation between that tweak with performance, only to improve battery life a bit longer.

 

These are similar to the settings done by NHC and RMClock. It changes the time it takes for the OS to see a % load before lowering or increasing the CPU speed.

By default XP is very aggressive on increasing the speed and safe on lowering the speed. Meaning as soon as it sees a load of more than 30% it'll increase the speed. But it'll have to drop to about 15% for 30% longer than it takes to increase the speed before it drops the speed.

I have no idea if it affects performance or not. I haven't tested it that deeply. I just tested it to see how it affect the time/load it takes to change the CPU speed.

 

I'm no longer running with battery in my laptop because if I place the battery, my keyboard becomes frozen. I can't type anything and I was confused of the relationship between battery and keyboard, so I just removed the battery altogether. My laptop has been running for a year without battery, just real electricity.

 

Sounds like you have a short in the battery. You should replace it or rebuild it. The only bad thing about runnig on straight wall power is you loose the UPS functionality of having a battery.

 

It is too difficult to say anything about it.

 

Any similar tweaks for Vista, or will this work as well?