Originally Posted by trparky
We don't know and I think that's the part that scares some people.
I think this might be due to some conception of switching involving having to "fire up" the second CPU and wait until it's up to speed, or something. (I had this image
In fact what would likely happen is that from the moment the system has decided to switch cores, the next program instruction would be processed on the second CPU and it would be a hiatus-free transition.
However, a potential for lag could be a failure of the system to decide in time that it needs to switch, therefore remaining on the lower powered CPU for longer than is advisable, causing the phone to be under-powered momentarily...