Isn't it possible to control how often InDesign autosaves your documents? Obviously my version, CS4, saves my 40 book documents every second minute and then I have to wait at least one minute before I can go on working. Maybe every 5 minutes would be sufficient!
I can't find any control feature anf InDesign help doesn't mention it at all.
There are no controls that you can access for writing the recovery files (which is the equivalent of an autosave, sort of). I doubt that the recovery file write is the problem, though, if you are having performance issues.
On very big preformance drag is cross-references, especially in books if they are inter-document references, and even more so if some of the files are closed.