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View Full Version : Speeddifference LW ppc to LW ub



ingo
04-04-2008, 06:16 AM
Just curious to know, whats the rendering speed difference between LW ppc and LW ub on an Intel Mac, and why ? Are "only" the cores not supported in Rosetta ??

Scazzino
04-04-2008, 10:48 AM
Just curious to know, whats the rendering speed difference between LW ppc and LW ub on an Intel Mac, and why ? Are "only" the cores not supported in Rosetta ??

The speed difference is very substantial.

The cores don't matter. Both versions can use all available cores.

The speed difference is due to the PPC instructions having to be translated before being executed on the Mac Intel. So each and every thing the computer has to do goes through extra steps... which in processor intensive applications, like 3D rendering creates an enormous overhead that saps much of the speed as well as taking up more RAM... so any scenes that barely render with available RAM on a PPC machine, may run out of RAM in Rosetta on a Mac Intel...

That said though, LW 9.3.1 PPC renders about 6 times faster (for some scenes) on an 8-core 3GHz Mac Pro (first rev) than it does on a dual processor 2GHz G5 (first rev) under Rosetta...

ingo
04-04-2008, 03:14 PM
Thanks for the info, i am still collecting money for a new Mac and just wanted to know.