So I had my first crash for no apparent reason (computer spontaneously rebooted). "OK", I thought, "I'll just load the last autosave", only to be disappointed to discover it was 20 minutes ago.

What is the default autosave frequency, and is there any option to increase it? Saves seem fast enough that there's no reason for it not to back up every 5 minutes, especially if it's going to crash after only 3 hours of play.