What I observed so far is that the translator chokes on large designs.
But neither CPU nor memory are at their limits…
You may adjust the default STEP Export settings for both ACE & FAB 3000 to drastically reduce conversion time and file sizes.
Crop the Design:
Many times only a section of the design needs to be extracted to 3D STEP for analysis and simulation. If this is the case, use both FAB 3000 and ACE 3000 ( command: Clip Area Wizard.. ) to crop out just the section of the design you require. This will drastically reduce file sizes and processing time.