Asus P8Z77-V PRO/THUNDERBOLT - Manual (Page 180)

5-10 Chapter 5: Multiple GPU technology support
Chapter 5
B1. If you cannot see the NVIDIA Control Panel item in step
(A), select Screen Resolution.
B2. From the Screen Resolution window,
click Advanced settings.
5.2.6 Enabling the NVIDIA ® SLI™ technology
After installing your graphics cards and the device drivers, enable the SLI feature in NVIDIA ®
Control Panel under the Windows ® 7 operating system.
Launching the NVIDIA Control Panel
You can launch the NVIDIA Control Panel by the following two methods.
A. Right click on the empty space of the Windows ® desktop
and select NVIDIA Control Panel.
The NVIDIA Control Panel window appears (See Step
B3).