I use VoodooPState.kext. Maybe that's not really necessary on a Pentium Dual-Core, but I don't really get the DSDT thing.
However, PStateChanger was a resource hog for me - it used >17% of the CPU in the lowest PState (Again, Pentium Dual-Core 2.0GHz). So I had a look, figured out that updating the GUI was the main fault, and rewrote the whole thing.
1. New Interface
- Less windows-y, more like cpufreq-applet from Gnome. Fits the Mac better. You can customize PStateMenu.app/Resources/cpufreq-xx.png if you don't like the images (google "cpufreq-applet icons")
- More efficient, uses less CPU
(Yes, the Meter works)
2. Switching based on the theory behind cpufreq-ondemand/conservative (http://www.linuxsymp...adi-reprint.pdf) from Linux (including later improvements):
- CPU utilization based on core with highest load rather than total
- On Demand: When frequency raising is needed, clock it to 100%, next time lower the pState if possible to a state which keeps CPU utilization around 80%
- Conservative: Smooth upscaling, not recommended by anybody, as ondemand clocks higher but gets work faster done. This is kind of what PStateChanger did.
- Switches every 0.18 seconds (CPUFreq switches every 0.11 seconds, but 0.18 cuts the cpu usage by 50% for me)
More or less as good as Linux (cpufreq-ondemand is written by Intel guys (Pallipadi et. al.)), AppleIntelCPUManagement.kext shouldn't be much different, too. This is basically a full-fledged Intel Enhanced SpeedStep implementation.
Version 0.2 (32+64Bit)
You find the latest VoodooPState.kext always on osx86drivers.sourceforge.net
Have fun with it.