UPDATE: Artem has written a very useful explanation on how to manually tweak those power profiles here: http://tutanhamon.com.ua/technovodstvo/NVIDIA-UNIX-driver Thanks for contributing!
You may definitely refer to that for a complete knowledge of nvidia power saving features, tips and tricks to tweak them.

New driver 169.07 features some performance enhancements for GeForce 8 series, but above all features the linux port of PowerMizer powersaving feature.

This technology works by autosensing the graphics computation requirements and autoadjusting the graphics’ card core and memory frequency, thus providing a noticeable amount of energy saving.

(Note: at this point it seems one cannot tweak either “Performance level” or “Performance Mode” settings, they are automatically set by the drivers. What you can do is tune maximum frequency by hand after enabling CoolBits)

Key Benefits are:

• Extended battery life
• Intelligently adaptation of performance based on a user’s needs so it saves power even when the notebook is plugged into the AC.
• Runs in the background to provide the best balance of performance and battery life (but only uses a 1s wakeup)
• Helps the notebook run cooler and quieter under normal operating conditions by dissipating less heat in the GPU

Working for both desktop and mobile chipsets, this is indeed of more interest for the latter.

If you wish to permanently set a certain PowerMizer level you can tweak your /etc/xorg.conf file adding one of the following strings under Section Device:

Option “RegistryDwords” “PowerMizerLevel=0×3″
to force the powersave frequency set

Option “RegistryDwords” “PowerMizerLevel=0×2″
to force the mid frequency set

Option “RegistryDwords” “PowerMizerLevel=0×1″
to force the performance frequency set

PowerMizer 7.0 Mobile Technology (specific to NVIDIA GeForce 8M Series of GPUs) delivers numerous mobile power management techniques to manage the power consumption of both the GPU and the entire notebook:

• Adaptive clocking and engine gating ensure the GPU is only consuming as much power as is necessary for the task at hand
• The GeForce 8M Series architecture is significantly more power efficient and utilizes the latest advances in chip process technology to achieve this
• Dedicated HD video processor to playback Blu-ray and HD DVD with the highest quality requiring less use of the CPU and thereby extending battery life
• More circuits using lower voltage rails
• More clocking and voltage scaling steps for finer control
• Support for GDDR3 memory at 1.8V
• NVIDIA SmartDimmer™ technology for intelligent, granular display brightness control for maximum battery life.
• ASLM (Active State Link Management) technology for ultra efficient use of the PCI Express link
• Uncompromised power management support for MXM-based notebooks

Even though Intel X3100 chipsets has features somehow similar, I must thank nVidia for putting this effort in developing good linux drivers.

(As many linux supporters I opted in buying nVidia powered laptops for the better support provided to the community, even though no OpenSource code is released yet).

Thoughts must also go to the United Nations awakening campaign for evironmentally aware citizens carried out last autumn. We must take action against environmental threats, saving energy is an important step towards providing a better future for our children.

http://www.nvidia.com/object/feature_powermizer.html