I have read all this PowerMizer stuff... it looks nice. On my notebook it underclocks the GPU when it's not used (350MHz to 100MHz for the core clock), and it works fine on the OS desktop even when some 3D effects are enabled (Beryl).
But that stops to work once you launch a game. Most 3D applications or games will just make a loop and try to render as much FPS as possible without any limit. This unables the PoweMizer temporary underclocking and the driver just increases the clock again for maximum performance.
I really miss a "FPS limit" option inside the driver. If driver is able to limit at 60FPS because of screen sync, it should be able to limit at 30FPS (or better... a value that I can choose). This option would be a real step forward for a more "green" gaming, or let's better say, less energy waste.
You think Nvidia employees are reading this forum ? I also asked here
I must admit that I only have this question since I'm using a E8400 + 8800GT desktop, and worry about the heat of my T5450 + 8600M GS notebook. My previous computers (PIII) where not able to reach even 40FPS in similar situations, and with lower graphic settings.