HP USB-C G5 essential dock (72C71AA) problems with 4k@60Hz

[mueller004]

I'm using a HP USB-C G5 essential dock (72C71AA) with an EliteBook 850 G8 in a configuration with 2 Displays connected to the dock: one FHD display with HDMI connector and one 4K Display connected via display port cable (cable is compatibel for use up to 8K).

So far I can get the 4K display working with 3840x2160@30Hz only - no 60Hz available. Even with a one display configuration there is no chance to get the 60Hz with that resolution. Connecting the display directly to the EliteBook via USB-C to HDMI cable it works with 60Hz.

So far I can just find specs describing the HP USB-C G5 dock 5TW10AA (not essential) and as far as I understand it should be possible to use it with a 4K@60Hz configuration. I can't find specs for the "essential" model. Whats the difference between those two docks (except the much lower price of the essential model)?

Is the essential model not capable of connecting 4K@60Hz?

Best regards,

Marcus

[banhien]

@mueller004 

Please check a table on the following document

              https://www8.hp.com/h20195/v2/getpdf.aspx/c04168358

I'm using my USB-C G5 and my HP 840 G5 now but I don't plan to buy a 4K monitor to test UNLESS one of my 5 monitors unusable.

Regards.

[mueller004]

I already found this document and if I understand it right, the 4K@60Hz should work. 

BUT: These specs are for the USB-C G5 dock and not for the USB-C G5 essential. Is the essential model kind of downgraded that leads to 4K@30Hz maximum?

Best regards,

Marcus

[kaysindre]

https://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c08339701&search=c08339701 

Here the Quickspecs for that specific model

[joeh2113]

Based on the Video Resolutions Table the other person posted. With the default settings for two displays one 4K and one FHD, the 4K display is limited to 3840 x2160 @ 30 Hz, unless the host has DP1.4MF w/ DSC.

If High res mode DP Alt mode is enabled, on the host then 3840X2160 @60Hhz regardless what DP version the host supports. If I am understanding the table correctly.

Instructions to enable High Res DP Alt mode - https://support.hp.com/us-en/document/c06575423

Hope this helps

Joel