Upvote:2
I see a roughly-four-hour ICE trip here (the specific trip is here). Some caveats:
Upvote:10
A connection of less than 4 hours is only achieved when using the special ICE Sprinter connections. Compared to the standard connection, these trains skip some of the stops. They leave both Munich and Berlin around 6:00, 12:00 and 18:00. The precise times can be found in the table on this page.
Secondly, the search as you entered it in Google Maps suggests taking a regional train from Berlin Central Station to Berlin SΓΌdkreuz and only enter the ICE there. This doesn't make much sense as the ICE stops at the central station as well and pushes the travel time over 4 hours.
I suggest using the search at bahn.com instead. It's available in a couple of languages including English.