While FXAA is lighter than using MSAA, it's still taxing on the graphics cards as shown from these Linux OpenGL test results. Unfortunately, though screenshots couldn't be captured due to the problems with that Timothy Lottes mentioned, but FXAA is a nice improvement although higher levels of FXAA do look better. At least though most mid and high-end NVIDIA graphics cards should be able to handle Fast Approximate Anti-Aliasing with decent speed when using the proprietary NVIDIA graphics driver. It would be interesting too if this FXAA support ends up getting integrated into Mesa from NVIDIA's open-source implementation.
Michael Larabel is the principal author of Phoronix.com and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated benchmarking software. He can be followed via Twitter or contacted via MichaelLarabel.com.