Intel GLSL On-Disk Shader Cache Enabled By Default

For Mesa 18.0 is the initial Intel shader cache support for archiving compiled GLSL shaders on-disk to speed up the load times of subsequent game loads and other benefits. For the Mesa 18.0 release the functionality isn't enabled by default but it will be for Mesa 18.1.

Right now if you want to use the Intel i965 Mesa driver's GLSL on-disk shader cache you need to have the MESA_GLSL_CACHE_DISABLE=0 environment variable set. But as of today on Mesa Git for what will become Mesa 18.1, the shader cache is being enabled by default. The shader cache is being unconditionally turned on now that it's matured enough and there hasn't been any severe fallout since the functionality landed back in November.

The on-disk shader cache that was introduced last year for RadeonSI Gallium3D in Mesa tended to help load times for many games and also help the frame-rates for some games that would otherwise be trying to recompile shaders on the fly. In our testing of the Intel shader cache, the benefits haven't been as great since the HD/UHD Graphics aren't as capable of running as many of those shader-heavy demanding games, but it still should prove to be useful over time especially with Intel graphics getting faster the next few generations ahead.