How large can a map be? Unfortunately, this is one of those 'how long is a piece of string' questions. It depends upon a number of factors that I'll go into in a moment - but there is a limit and when you hit it, the app will 'crash'. Actually what will happen is that iOS will decide that it's using too much memory and kill the app - but to the user, it looks like a crash!
What factors affect the max map size?
- Device type. The original iPad1 had 256MB of memory whereas the latest iPad Air has 1GB (4x as much)
- How many (and what type) of other apps are running also.
- How much AREA on the screen is used by topics.
The last point is the one to concentrate on. Each topic will use memory that is proportional to the area it takes up on screen. So large topics or zoomed in topics will use more memory. Topics that are 'collapsed' (hidden) use almost no memory - but topics which are 'offscreen' use just the same as those actually visible.
Crashes (out of memory issues) are often noticed first when zooming in on a large map since that increases the area of the topics rapidly and massively.
Tips to avoid out of memory issues:
- Avoid large topics. Topics with lots of text or large text or images all use lots more space. Oval topics use more space than their rectangular counterparts.
- Avoid zooming in. Zooming in to 200% will quadruple the area taken up by topics (and thus quadruple the memory required.)
- Avoid large numbers of topics that are permanently visible (i.e. try to keep branches collapsed.)
- Break up large maps into sub maps and use hyperlinking to knit them altogether - see here.
All that said, your typical mind map with upwards of 1000 topics is usually fine. Many people have maps with a couple or three thousand topics. It depends!
If you are unable to even open a large map, then you can try the follows:
- Open 'System Settings' (under the gear toolbar button)
- Scroll to the bottom and set 'Collapse branches on load' to ON
- Open the offending map.