Best Way to Connect External 60Hz 4K Display?

Does the XPS15 have the right stuff to drive a 60Hz 4K external monitor?
If so, which connector out?
And will the Photoshop UI at 200% on a 27" 4K look right?

 

I would like to know this too as I can't seem to get the 4k resolution to show up as an option when connected to my HP 27" Envy 4k display. I've tried both directly through HDMI to the laptop and through the WD15 dock using the USB-C connector to the laptop. What gives?

 

I use this: https://store.google.com/product/usb_type_c_to_displayport_cable

 

60Hz 4K only via a TB3 connector (USB-C plug but not USB connection). That would be a dock like the TB16, or at least a TB3-to-DP adapter (but then no other TB3 connection left).

 

So not even the WD15 dock would work? The specs in the manual indicate that it does work via DP.

 

The dock should work just fine and might even be a better option if you have the space for it since it would give you additional ports.

 

I'm actually using the WD15 dock, and still cannot get 4k resolution on my external monitor, no matter what connection type I try.

 

The WD15 specs aroud the web differ somewhat. One instance mentions 4K@60Hz but with a particular cable "Universal cable with Thunderbolt system". Mostly a single 4K@30Hz is given as the upper limit. Another instance doesn't mention 4K at all...

https://www.dell.com/support/articl...roubleshoot-the-dell-dock-wd15?lang=EN#Issue5

http://www.dell.com/support/article...mation--capability-and-specifications?lang=EN

http://iteraction.ee/wp-content/uploads/2017/03/Dell-dock-WD15-spec-sheet.pdf

https://www.dellpoint.pl/pl/p/file/2e7215dbf53036ce66b47decf07eaf08/wd15.pdf

 

So given the uncertainty around all of this, what is my best option for 4K connectivity to an external monitor from the XPS 9550?

 

I think the WD15 should work at 4K 30Hz. Check https://www.reddit.com/r/Dell/comments/4mqaci/4k_60hz_issues_xps_9550/ for instance, only complains about not getting 60Hz. I think you've got a driver issue. Which Intel HD video driver are you using, and where from (Dell or Intel)? Intel may not be aware of WD15 using USB type-C alt-mode for video.

There's a discussing regarding WD15 and 4k@60Hz using that Universal USB/Thunderbolt cable, but likely it was never spotted in the wild, and even the TB15/16 cables supposedly don't fit due to certain prongs.
https://www.reddit.com/r/Dell/comments/5hw5t0/idea_how_to_run_a_4k60hz_with_wd15_docking_station/

You can also consider 3rd-party TB3 docks or display adapters. I'm waiting for something cheaper and more compact than what's available now.

 

At first I was using Dell's version of the Intel HD Graphics but have since removed it using the DDU uninstaller and re-installed drivers v4627 from Intel's website, their latest version. I still do not see any 30Hz modes or the 3840x2160 resolution available in any of the modes. I've tried connecting to my WD15 dock using HDMI and DP, same result.

At this point, I'll consider anything that will just work - it shouldn't be this difficult. I'm afraid to buy any more cables/docks as they may all have the same issue - not sure.

 

So I finally managed to add a custom resolution but was limited to adding 3840x2160 @ 30Hz. I guess the WD15 dock cannot produce 60Hz refresh rates? Gives me a message saying no bandwidth for those specs. Anyone know if the new TB16 dock supports 60Hz refresh rates? I wonder if the issue is the WD15 dock or the laptop itself.

 

What did you fix to get 4K?

As I already replied, 4K@30Hz seems to be the limit with the WD15 as is, and the bandwidth warning makes sense. The manual states that it might be able to do 4K@60Hz with a particular universal USB-TB cable which has more DP lanes, which was not spotted in the wild AFAIK. One could try with the TB15/16 cable, but would supposedly have to remove certain prongs that prevent connection. Try asking Dell if that cable happens to be available.

 

I reinstalled all the drivers again and this time selected 30Hz as the refresh rate - I believe the problem was I kept trying to add the custom resolution with 60Hz. It's silly to me that we even have to add a custom resolution to get it to use 4k resolution - it should be made available automatically. Nevertheless, at least I have 4k resolution now... I think this is manageable until we get more clarity on which devices/cables will work flawlessly. Thanks for the feedback.

 

I am running a Dell XPS 15 connected to a 4K LG 27UD68P External Monitor via HDMI 2.0 cable (Belkin) with a Dell HDMI 2.0 to Usb-C Adapter. 4K resolution @60Hz.

 

As for me...been using this single USB-C to DisplayPort Cable since around May of last year to connect my XPS 9550 directly to my Dell P2715Q monitor @ 4K/60Hz.

Also, Photoshop runs and looks perfectly fine set @ 200%. I've also got Windows 10 'Display Settings' set to 200%. A-okay for me.