[BillSwagger]

i used this mod which gave me a slight gain in frames, but what made a greater difference was shrinking the 4x4 tga texture to half the original size.
The only difference i can see is that the clouds look hazier, which i think is also more real looking.

So if you aren't getting decent frames with this mod, just try shrinking the texture file.
I was getting 20 frames in clouds at 1280 x 960, and now its closer to 30.