Here's some more info I posted on NVIDIA Developer Zone
I've been using Steam to play DOTA 2 on my Linux Mint 14 64bit box with my GT 520 but today it suddenly stopped working. Whenever I try to launch DOTA I get the following message:OpenGL GLX context is not using direct rendering, which may cause performance problems
and I'm giving the following unhelpful link: https://support.steampowered.com/kb_art ... -EYZB-7457
I'm running the NVIDIA drivers as managed by the Software Sources tool in Mint 14. Worked fine before this. The NVIDIA X Server Tools util says I'm running NVIDIA Driver Version 304.88 and X Server Version 11. The OpenGL/GLX Information tab has the following contents:
Direct Rendering: Yes
. Lots of uninteresting GL stuff etc
Version: 4.2.0 NVIDIA 304.88
I'm not that familiar with the video card issues on Linux so please let me know what other information may be useful for debugging this, and let me know if you know a solution!