4. Powermizer 5.0

NVIDIA refers to the Go 6800's power saving features as "Powermizer 5.0". The common goal here is to make sure the GPU only consumes exactly the amount of power required for each specific task. However, the changes from Powermizer 4.0 basically concern MXM validation. All known features have already been optimized, and the algorithm responsible for balancing CPU and GPU load has been refined. According to NVIDIA, Powermizer 5.0 now offers smaller voltage increments for supplying either the whole GPU or certain functional parts. Clock gating has also been added.

Notebook users can easily adjust 3D performance and hence directly influence the power consumption of their GeForce Go 6800. There are, however, some features that cannot be altered:

Dynamic clock and voltage control Dynamic clock gating Software based load balancing between CPU and GPU; for example, by the CineFX 3.0 engine or the integrated video processor Automatic enabling/disabling of components that are not in use (e.g. TV out)

Three settings are available:

Maximum Performance Balanced Maximum Power Savings

The basic idea behind this software algorithm is rather simple: as the clock speed of the GPU and video memory decreases, these components require less power. More power can sometimes be saved by controlling how much workflow is transferred to the CPU, indirectly influencing its power requirement.

From a gaming standpoint, hundreds of frames per second may look pretty good, but that is definitely not a must-have in order to have fun. Hitting the desired frame rate does not require the CPU to run at full clock speed. Since the processor and the display are the most critical energy consumers still today, combining both mechanisms can save enough energy in order to prolong battery life considerably. That is the theory, since an energy-eating desktop processor or a huge and bright display easily destroys efforts at extending battery life.

Selecting "Maximum Power Savings" causes the GPU core and video memory to run at minimum clock speeds. As a result, frame rates will of course be pretty low. "Balanced" aims to distribute workload between CPU and GPU in a most efficient way, in order to keep CPU power consumption within acceptable boundaries. Here, the system will deliver much better frame rates. Finally, "Maximum Performance" ignores energy consumption, and will have your graphics unit delivering the best frame rates. You should not expect much battery life at this setting, naturally.

NVIDIA's GeForce Go 6800 driver also offers a feature that allows automatic display brightness reduction. Unfortunately, notebook manufacturers have not yet integrated the dimming feature into their customized drivers. This really is a major loss, since reducing brightness is a very simple and rather obvious way of saving energy.

Smart Dimmer's user interface looks pretty similar than the Powermizer's. Users can set the minimum brightness for notebook inactivity using two sliders here.