carstenquilitz, did you maybe not use all 8 cores? The reason I ask is that aitraaz posted his speed test with the same Mac, and rendered it in 19:48 which is a 3:30 min difference. The only difference I see between the two is that he is using XP64 rather than the Mac OS.
However, tcamco also posted a result almost the same as yours with the same setup (23:12), so maybe aitraaz has something else going on with his setup?
I used all 8 cores to run the test and I believe maxwell for OS is be a bit slower than the XP Version. Will do a test on XP once I have installed it on this machine.
Q! Berlin
Cinema R20 - Rhino - Maxwell Render on 318 Core CPU Ranch Mobile Renderfarm - OS X+WIN X http://www.carstenquilitz.de
Interesting, I didn't know that. I think the difference is a little more than a "bit slower" though. A 3:30 min gain on a 23 minute render is huge for simply changing the operating system!!