Blender crashes when rendering scenes from Nature Academy? It’s likely that grass particles cause Blender to run out of RAM. While I have explained the theoretical RAM limits in an article before, this article is more about the practical limitations.
In general, I assume that you are using the 64 bit version of Windows and 64 bit version of Blender, which gives you a theoretical memory limit of 16 TB. But where does this huge amount of memory come from? It comes from the physical amount of RAM you have installed and the size of the page file (pagefile.sys).
Now, the page file can grow at maximum to the full size of your hard disk, which typically means that the limit is below 500 GB, which is far away from 16 TB. In the beginning, Windows will not make the page file so large – otherwise you would not be able to store anything else on your hard disk.
Windows starts at around 2 GB or 4 GB and expands the page file when needed. However, Windows might not be as fast at expanding the page file as Blender requests more memory. If this happens, Windows does not allow Blender to get more RAM and causes an Out-of-memory exception which crashes Blender.
Next time you start Blender, the page file is already bigger, e.g. 8 GB, and will be expanded again. It may then happen that Blender renders your scene as if it would never have had any problems. It might even happen that you can increase the particle count without any issues.
So what is the practical memory limit on your PC? In order to figure that out, I have written a small program which does nothing else than allocating memory. It does that in 4 MB pieces and it will recognize the limit before it actually crashes. It will then tell you, how much it was.
Be aware that running the program twice may cause different results. This is for mainly two reasons:
- the page file has been expanded in the meanwhile (as explained before)
- other programs running at the moment the memory limit is tested. This may also be invisible programs such as automatic update or virus scanners.
I’m sorry I have only German versions of the screen shots.
This program requires the .NET 2.0 framework to be already installed on your computer.