Using NVIDIA SLI technology with multiple NVIDIA GPU-based graphics cards gives the best rendering performance in your Direct3D and OpenGL application content.
Note: To use this procedure, you must be running on an SLI-ready computer that is properly installed with two or more NVIDIA GPU-based SLI-ready graphics cards.
To use NVIDIA SLI technology with multiple SLI cards
From the NVIDIA Control Panel navigation tree pane, under 3D Settings, select Set SLI configuration to open the associated page.
Under Select the SLI configuration, click Maximize 3D performance.
The GPU configuration visualizer shows the pending SLI configuration as well as the display connections and enabled state of the displays. The SLI bar indicates the SLI mode (SLI, 3-way SLI, Quad SLI, or 4-way SLI) and points to the GPUs that are used for SLI.
Click Apply.
If you have more than one display connected,
Windows XP or pre-GeForce 8 series GPUs
You can select which display to use to view your game. Use the Set up multiple displays page to select which display to use as the primary display. The GPU connected to this display will function as the "primary" GPU, all others will function as slaves to the primary GPU.
If none of the displays in the SLI group are the primary display, then the driver will select which display to use to view SLI-accelerated games.
Windows Vista or later, and GeForce 8+ series GPUs
You can select which display to use as the SLI focus display, or the display to which you want to apply full SLI acceleration for full-screen applications. Use the Set up multiple displays page to select which SLI display to use as the primary display. This becomes the SLI focus display.
If none of the displays in the SLI group are the primary display, then the driver will select which display to use as the SLI focus display.
Note: You may want to disable SLI technology if you experience software compatibility issues with 3D applications.