thin wall refraction is too slow to render

[chadsmith]

i have rendered an image that had the thin wall refract map. but, i set it to render then came back hours later. it will actually start rendering the image BUT it is taking an eternity to "render reflect/refract map". seriously.. 8 hours sometimes.... i just cannot seem to get the thin wall to render faster. any thoughts besides post production?

[nisus]

Raytrace map with maximum depth to 2 or 3