Do I need a special graphics card for a 4K monitor?
Is my Intel HD Graphics 520 with an i7 6th generation sufficient?
It would be a shame if I couldn't use the monitor I bought...
The 6500U supports a maximum of 4096x2304@24Hz via HDMI. This is "real" 4k, i.e. 4000 pixels. However, with our usual resolution of 3840x2160, you get 30hz.
As for the question of whether 30hz is enough or whether you need 60hz, it's a bit like the question of whether Android or IOS is better. There is simply no right or wrong, it depends on your personal attitude. For me personally, 60hz is a must, mainly because I play a lot of games and really enjoy the additional smoothness of 4k.
However, 60hz is not a must. To write a letter in Word or make a few calculations in Excel, 30hz is perfectly sufficient, and you can also watch a film or YouTube with it.
It all depends on what you want to do on the screen.
Yes, that's enough. At least as long as you need the monitor for light tasks like office or YouTube. But you won't be able to do gaming, photo or video editing and similar hardware-intensive applications with the 520. It is best to connect the monitor via Displayport and not via HDMI. That way you also have the full 60hz.