I cannot run the laptop (intel HD graphics 630) with external 4K monitor in 3840x2160 resolution with 60Hz frequency.

[JToka2]

I need to add that the cable is HDMI 2.1 and it is not problem related with the monitor or cable, because by the use of PC working station everything works ok. I checked it on Dell XPS 15 9560 and HP Pavillion 15. Still the same - 30 HZ, 4K.

[n_scott_pearson]

If you are connecting this display to the HDMI connector, then yes, you can achieve only 30Hz. Why? Because the laptop's connector is only compliant with the HDMI 1.4 specification.

If you want a 60Hz display, then you need to connect to the USB-C/Thunderbolt 3 connector. This connector exposes a Displayport 1.2 channel that will support 60Hz. You can use a monitor with a direct DisplayPort interface or use a USB-C-to-HDMI dongle or cable that converts to HDMI 2.0. Look for one that is also compatible with Thunderbolt 3. Here are examples:

C​able: https://www.amazon.com/Adapter-QGeeM-Thunderbolt-Compatible-ChromeBook/dp/B073J9ZZY6.

Dongle: ​https://www.amazon.com/Anker-Aluminum-Pixelbook-Compatible-Thunderbolt/dp/B07THJGZ9Z.

H​ope this helps,

...S