How many monitors are supported when running in SLI mode?
With GeForce R180 drivers, SLI supports a maximum of two monitors with both monitors connected to the same GPU within your SLI group. For instance, if you have a 3-way SLI configuration, you can connect two monitors to one of the GPUs and leave SLI enabled. You can enable more monitors by using a third GPU that is NVIDIA PhysX capable (GeForce 8 series and higher with at least 256MB of memory) and is a different GPU than your SLI GPUs. For example, a configuration with two GeForce GTX 280s in SLI and a single GeForce 8800 GT is capable of supporting six monitors.