Cannot select 4k@60Hz with Intel UHD on DisplayPort

[YesYesYesNo]

Hi everyone, 

I'm currently using a laptop with i7-10610U CPU and Intel UHD Graphics. 

Not matter what I try, I cannot select 4k/60Hz resoltution either on Windows 10 

advanced graphical settings or Intels Graphics Center. 4k@30 Hz works fine with

my attached Dell S2721QS Monitor, as does anything < 4k with 60Hz.

Trying to set the resolution and refresh rate manually in Intel Graphic Center results

in an error saying it's unsupported. Attached a dxdiag. 

Anyone an idea on how to fix this? The graphics card should be able to run this 

resolution on multiple monitors. I'm connected via Lenovo USB-C Dock and DisplayPort

cable. 

Thanks a lot!

[n_scott_pearson · Accepted solution]

You have a DisplayPort channel that is capable of supporting a 4K@60Hz connection, but (and it's a big 'but'), when you use USB-C to connect both USB (even just the USB Hub in the dock) and DisplayPort devices, only half of the DisplayPort bandwidth is going to be available and thus 4K@30Hz is the best that you are going to be able to do.

Sorry, reality bites,

...S

P.S. If you use that USB-C port to connect *only* the monitor, you will be able to do 4K@60Hz. This presumes you are using a USB-C-to-DisplayPort or USB-C-to-HDMI adapter/cable, NOT that dock nor a USB-C-to-USB-C cable (this latter would be creating a similar bandwidth reduction due to the USB Hub implemented in the monitor).

[YesYesYesNo]

Wow, thank you very much for that quick and thorough answer!

You're right, I am using a full USB-C Dock by Lenovo which also serves as USB Hub. 

The bandwith reduction applies to HDMI as well, unless you connect the cable directly to the laptop. 

I had done this in the past and recognize that I could indeed go to 60Hz this way. 

For everyone else finding this thread: 2K/60Hz is working well in this scenario and is now my fallback resolution.