Custom matcap performance

Hey guys, i created some custom matcaps for sculpting the other day. I use the textured viewport mode with GLSL shading with a shadeless material. The matcap texture is mapped to the object by the normals. When i sculpt in dynamic topology mode (and only then), sculpting with these matcaps gets laggy, when my object hits like 300k polys. I tried lowering the texture resolution with no success at all. So my question is: Did someone have similar experience and does someone know a fix to that and is kind enough to explain it to me :slight_smile: thx in advance and happy blending!

Chris