Jim Burton did a speed survey using a pz3 benchmark file with Poser 5. Quite a few people responded, and the results indicated that Poser 5 renders the scene about 3 times slower for G4s and G5s than for Wintel boxes of the same clock speed. E.g.: IIRC a 1.8 GHz G5 runs the render at the same speed as a 600 MHz Pentium (around 92 seconds). This is the only 3D app I know that is slower in OS X than in XP Pro. All the others are faster AFAIK.