Comment 8 for bug 1222602

I did not realize that the opengl conformance level is /already/ configurable via the MESA_GL_VERSION_OVERRIDE environment variable.

Setting it to 1.4 in /etc/environment is actually sufficient to restore the unity desktop functionality on the EEEPC (and - I guess - on machines with < gen4 hardware)

This is good news, because the environment setting is a sufficient hack to make latest mesa work with gen3 hardware in todays DMs.

However, I wonder, why is the advertised opengl 2.1 functionality so unberably slow on gen3? Is mesa rendering on the CPU for this (seems so, as the cpu load goes extremely high when unity tries to open the logout panel)? Is it sensible to do so by default, since machines with gen3 cannot be expected to have strong CPUs?