Set Multi-GPU and PhysX configuration (reference)

The Set Multi-GPU and PhysX configuration page is available if your system has

Two or more NVIDIA-based GPUs in a non-SLI platform, and
One or more PhysX-capable GPUs

Multi-GPU configuration

Disable multi-GPU mode: This option lets you run all GPUs to run independently. You can also drive multiple displays on each GPU.
Maximise 3D performance: This option lets the driver make the GPUs work together in SLI mode, when possible, to increase rendering performance of 3D applications.
Span display with Surround: This option lets you combine multiple displays to act as one larger display to allow a panoramic view of full-screen games or your desktop.
Activate all displays: This option enables all available displays. If possible, multi-GPU rendering may still be enabled.

PhysX Settings

Processor

Auto-select (recommended): This option lets the NVIDIA driver select the best processor for PhysX.
<specific GPU>: This option causes the GPU to be used to accelerate PhysX processing. If the system has more than one PhysX-capable GPU, then you can select which GPU to use for PhysX GPU acceleration.
CPU: This option causes the CPU to be used for PhysX processing.

Dedicate to PhysX

If you want to use your selected GPU only for PhysX and not for SLI rendering, click the Dedicate to PhysX check box.

NOTE: The Dedicate to PhysX setting can change if you change the multi-GU configuration.

GPU Configuration Visualiser

The GPU configuration visualiser shows the system configuration for the current selected options. The selections do not go into effect until you click Apply. The visualiser shows:

GPUs in the system
Enabled and disabled connectors
Enabled connectors can drive displays, whereas disabled (greyed out) connectors cannot drive displays. The connector state depends on the configuration options you select, and can change if displays are hot-plugged.

For notebook PCs, the connectors shown may not match your hardware - for example, if you are using a docking station, then the connector on the docking station may not be indicated in the visualiser.
Displays connected
Inactive displays are greyed out. SLI focus displays are identified with a green outline.
PhysX configuration
The PhysX cloud above the GPUs indicates that all the active displays benefit from PhysX, and points to the GPU that will be used for PhysX processing. If there is no pointer, then the CPU has been selected for PhysX processing.
Multi-GPU configuration
The multi-GPU bar under the GPUs points to the GPUs that are working together to increase rendering performance.