[deaddodo]

They have a support matrix on their site[1].

The short of it is, every card has 2d support. There are very few lacking 3d acceleration. Newer cards have flimsy video acceleration. Power management is severely lacking across the board. Specific advanced features are hit or miss. Performance is still behind the proprietary driver in every case I've seen; but for cards from the 200 to 700 series, it's a smaller drop-off than newer cards.

I'd recommend giving it a try and see how it works in your specific use case. I've personally never found a case where nouveau works well enough to drop the Nvidia driver, but I'm usually on the latest or next to latest gen.

[1] - https://nouveau.freedesktop.org/wiki/FeatureMatrix/