The Fastest NVIDIA GPUs For Open-Source Nouveau With Steam Linux Gaming
At least with Portal the GTX TITAN and GTX 780 Ti were running faster than the HD 6770 when using the latest open-source drivers, but the performance still has a long way to go.... Even a GeForce GTX 460 couldn't play any of these Source Engine games due to lack of re-clocking and its boot frequencies being extremely low.
The open-source Radeon driver support is shaping up well... Even for the Radeon R9 290 it's starting to play well on a fully open-source software stack but there's still a few lingering issues.