But at least for me it's not a show-stopper, just a mystery. Sorry that my advice is 'live with it' but I don't have a solution. I suggest you simply shrug your shoulders and go do something else while it's rendering. QUESTION: Does it render correctly, and does it finish? If so. What to do? I put the investigation on hold and continued on with my project.

Strangely, even the slow-rendering projects play without any problem in the real-time preview. But in each case I had other projects of similar complexity that rendered at a 'normal' speed. Theories included it having something do with lighting, or the number of cameras (thinking it might be 'rendering' all camera views instead of only the active one), or the amount of trees. I would like to know what causes the difference, but my first couple of ideas didn't pan out. (I haven't noticed if the first few frames are fast, but I'll have to look for that next time.) Other projects render quite nicely. I have a couple projects that render very slowly, like you described. The same rendering situation happens with very small project files

Same project, same situation and results as above, but when I go EXPORT, either full HD or any other smaller Video format, rendering is fast for the first 60 frames, then very slow, say more than 1 sec per frame. In EXPORT: Rendering a full HD video (1920x1280) MP4, AVI or WMV is pretty fast. I continue clikking OK and it seems to work correctly. When Project file is larger than about 500.000 KB, during the opening of tht project, iClone Reminder tell me that: 'Free Disk Space on Disk D (or C) is insufficient. 1 (latest patched version) is running under Windows 7 Ultimate - Service Pack1 (always updated):

Iclone 5 full version 32 bit