This must be embarassing. After Nemetschek posted benchmarks showing that the Vectorworks on the G5 outperforms Vectoworks on the Intel Xeon, the company is being required by Apple to switch over to Intel CPUs.
The benchmark tested:
2D Redraws -- general 2D CAD drawing performance.
Renderings -- calculation times.
Solids Modeling -- modeling operations.
Architosh asks the question, "What's going on to make this [G5] machine so quick?" The Nemetschek CTO admits he doesn't know why. Now it no longer matters; the answer will be assigned to the dustbin of history.