Nvidia NFORCE 780I SLI - Manual (Page 110)

780i 3-Way SLI Motherboard
NVIDIA Corporation
100 October 17, 2007 | DU-03597-001_v01
Enabling 3-Way SLI
3-way NVIDIA SLI is enabled from the NVIDIA Control Panel . Right mouse
click on the Windows desktop and select NVIDIA Control Panel. Go to 3D
Settings Ú Set SLI configuration (Figure 19) and select Enable SLI technology
(recommended) . After selecting this option, you will be prompted to verify the
settings have been successfully configured.
Note:
Selecting Do not use SLI Technology sets the configuration into single GPU
mode.
Figure 19. NVIDIA Control Panel, Set SLI Configuration