I took the Amsterdam to Berlin route a few days ago with almost two hour delays because of some diversions. There are very few proper high speed tracks in Germany. Mostly the trains are routed over older tracks that aren't suitable for higher speeds.

Basically the only stretch where the train to Amsterdam might hit anywhere close to its maximum speed is the 20% of the journey between Berlin and Wolfsburg. And even there it slows down frequently. But you might see it go 250 km/hour for a few minutes.

I took a proper highspeed train from Madrid to Valencia a few years ago. It goes 300km/hour. It leaves Madrid, accelerates. And then a bit over 1.5 hours later you arrive in Valencia. It's about 400km. The train has one stop about mid way. Otherwise, it stays at its maximum speed the whole journey. At that speed, Amsterdam-Berlin should be doable in a bit over 2 hours.