[not reporting bug] Sometimes gases load up like this, would this be better for fps?

[ozymandias_3]

 

and how can i turn it on purpose

[Coolthulhu]

Looks like the gas texture failed to load.

Pretty sure that the effect on FPS should be unmeasurably small to inexistent, since the shader is probably compiled with texture in mind and just substitutes an empty texture if it can't load the proper one.