According to this thread apple have made it not possible. Seems like people are trying to hack it. I'm sure RV plays stereo though.

But, from what I've seen, it depends of what OS X version you are using.

OsX is based on FreeBSD, (a POSIX variant of Linux) and it's the same driver. You can try to start "nvidia-settings" in a terminal to see the options.

If you don't have those options, that VERY possible, usually, you can set them anyway on the card "by hand". That means you have to add some options to the Xorg server (the program handling the display) in the command line or the config files.

However, I don't have all the commands you can put there. I know there are a lot but that's something you would need to look on the Nvidia driver whitepapers.