Texture caching (and lower memory consumption)  ONLY works if the texture filtering is set to quality or crisp on all the textures loaded.

If at render time your memory jumps out of control, check that you have NO textures set at Texture filtering NONE !

**That goes for all textures.
**
Trees?
Do you have tree transmaps set at texture filtering NONE???

Set all textures to crisp, and check again.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!