Hi Dan - running out of RAM with 32-bit MoI won't really have much to do with things going slower - if you run out of RAM things just won't work at all, like chunks of the model won't end up getting loaded at all or things like that. But basically things just won't work at all, it's generally not that they will work but more slowly.

The main time that running out of memory is related to running more slowly is when you have a machine that has less than 4GB of ram and it's used up all available physical ram and is using "virtual memory" instead where it's swapping chunks of existing memory out to disk in order to free up more of the limited physical RAM. That does cause a really major slowdown when that happens, but that will happen if you're trying to run a scene that uses say 1GB of RAM on a machine that only has 512MB of RAM. This "excessive swapping" type of slowdown won't happen at all on high memory machines since MoI can't even fill up the entire physical RAM to start with.

That does remind me though, there is a difference in max memory with MoI between OSX and Windows - on Windows MoI can use up to 4GB (in practice more like around 3.6GB), while on OSX it will max out at around 2GB instead. That is something that I may be able to fix, it is on my list to investigate in more detail.

I guess it is possible that if you were right almost exactly at the limit it could make for some strange operation with a lot of things ending up sporadically failing. But you'll probably end up just crashing instead of just running more slowly.

- Michael