Thanks to one of our readers, we have some early benchmark results on a 17" 1.8 Ghz G5 iMac.
Cinebench results:
CINEBENCH 2003 v1
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Processor : iMac G5
MHz : 1.8 GHZ
Number of CPUs : 1
Operating System : 10.3.5
Graphics Card : 5200
Resolution : 1440x900
Color Depth : millions
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Rendering (Single CPU): 243 CB-CPU
Rendering (Multiple CPU): --- CB-CPU
Shading (CINEMA 4D) : 228 CB-GFX
Shading (OpenGL Software Lighting) : 558 CB-GFX
Shading (OpenGL Hardware Lighting) : 695 CB-GFX
OpenGL Speedup: 3.05
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and an Xbench score of 134.71 (full Xbench details in thread)