Thanks, Terry. I guess that your GPU is the AMD Radeon HD 6750M. I've tested with an AMD also (HD 4870 1 GB).
To me, this test shows that:
1, With shape 1 (plane, low poly count), Max 5 is 2 to 3 times faster than Max 6.
I know that Max 6 had many changes under-the-hood. Maybe some of these changes introduced a bug? I hope so... can anyone from Cycling comment/confirm this?
2. AMD graphic drivers on Windows perform much better with high poly count (shape 2) than on Mac OS X.
If anyone has a system with dual boot (macintosh, hackintosh), I would like to confirm this... and to also have results from NVidia cards!
Thanks everyone.