Intel Fixes Anisotropic Filtering For Their OpenGL Mesa Driver
Phoronix: Intel Fixes Anisotropic Filtering For Their OpenGL Mesa Driver
Intel Linux developers have enabled EWA Anisotropic Filtering support within their Mesa 3D driver after discovering their classic AF support might have not been working...
Not likely it wasn't working anywhere
Old anisotropic filtering algorithms often failed to work at certain particular angles, and therefore when the hardware got faster vendors implemented better (but slower) algorithms which would work all the time instead of just 90% of the time.
Sounds like exactly what happened here. The test was just designed to show off the weaknesses the old algorithms had.