performance tests / cube with rounded corners (openSCAD)

I did some performance tests on different functions, which all produce a box with rounded corners. You can find them in the scad-file.

Here are my results:
PreView Render STL-Size
v1 1 seconds 0 seconds 5.911.647
v2 0 seconds 215 seconds 3.773.709
v3 1 seconds 0 seconds 2.053.339
v3a 121 seconds 0 seconds 2.053.339
rB 0 seconds 171 seconds 3.648.521