Support for 1x4k + 2x1k Monitors with Intel(R) UHD Graphics 620?

[TGMusser]

I have a Dell Latitude 5400 which includes a Intel(R) UHD Graphics 620 Display Adapter.  Attached is the DxDiag report for this system.

I'm having trouble determining if the following configuration will work.

I am planning to connect 3 Monitors using the following.

     Dell Thunderbolt Dock - WD19TB

     DELL P2721Q 3840 x 2160 @60 Hz connected to Display Port

     DELL P2419H 1080 x 1920 @60Hz connected to Display Port

     DELL P2419H 1080 x 1920 @60Hz connected to HDMI

Would you please verify this for me?

Thank You and Best Regards,

TGMusser

[n_scott_pearson]

This likely isn't going to work the way that you think it will...

• Regardless of how they are connected, the processor graphics engine supports a maximum of three monitors. Your description includes 4 monitors, 3 external monitors plus the laptop's display. Unless the laptop's display is disabled, only two external monitors will be connected. It is unclear whether the laptop actually disables its display when the lid is closed.
• The dock is connected to the laptop using a single Thunderbolt 3 connection. Regardless of the transfer capabilities of the connection, what's available is a single DisplayPort 1.2 channel. This channel can throughput 17.28Gb/s. A 2160p@60Hz monitor requires a throughput of 12.54Gb/s. A 1080p@60Hz requires a throughput of 3.20Gb/s. 12.54Gb/s + 3.20Gb/s + 3.20Gb/s is greater than 17.28Gb/s. Likely what will happen is you will get 2160p@30Hz and two 1080p@60Hz connections.

Hope this helps,

...S

P.S. Calculations based upon charts in Refresh frequency limits for standard video section of this article: https://en.wikipedia.org/wiki/DisplayPort.

[TGMusser]

Hi Scott,

Thank you for responding!

I think there may be a bit of a misunderstanding.  Probably should have clarified things a little more.

My description shows 3 monitors, not 2.  My laptop display is disabled as the lid is closed while it's docked.

I've currently got 2x1k displays and want to replace 1 of them with a 4k screen, if possible.

I do agree that the total throughput is not enough to support my intended design at 60Hz each.  In this case, I am okay with the 4k display being at 30Hz as this would just for Windows apps; no 3d graphics, video production, streaming, etc.

Maybe I just need to go with a 2k display instead of 4k...

TGMusser

[n_scott_pearson]

You could certainly substitute a 2560x1440 monitor for the 4K monitor and still achieve 60Hz.

...S