1 Nickel

Trouble with XPS 15 9550, USB-C/Thunderbolt 3, and external monitors

After the time spent with Dell Support doing diagnostics and updating video drivers to those official Dell drivers on the support page, my new XPS 15 9550 with 4K touch display continues to struggle when using external monitors. I have two (2) Dell U2515H monitors.

I have updated ALL of the drivers and BIOS to the very latest files available on the Dell support page, including the newest Thunderbolt 3 driver.

When the laptop is NOT connected to any external monitors, I am NOT experiencing any trouble.

When the laptop is connected to ONE external monitor via the onboard HDMI port, I am NOT experiencing any trouble.

Trouble begins with the addition of ANY external monitor via the USB-C/Thunderbolt 3 port.

I have experimented with the following three adapters, all producing the same result:

  • Dell USB-C to HDMI (2.0), part number 047KD7
  • Dell USB-C Port DA200, part number 5KMR3 REVA00
  • Cable Matters USB-C to DisplayPort
First, regardless of which adapter. my laptop ramps up the fan for as long as the adapter is present.
Second, although the monitor works with any of the adapters at the proper resolution, all of the screens will go black about every 10-20 minutes and the displays will seem to resize and reset. In this process, about half of the time, the windows open on the monitor connected to the USB-C/Thunderbolt 3 port will either minimize or relocate to the primary display (the laptop screen). However, the laptop itself doesn't freeze. I tried running a YouTube video through the screen freeze event. The sound continued without any trouble and the video advanced through the timeline and was synchronized to the sound when the displays reset.
If I disconnect the USB-C adapter (whichever one), the laptop fan will return to an idle state and the display freezes also stop.
I think that the USB-C/Thunderbolt 3 driver and/or the external display driver is/are to blame and I strongly urge that Dell get this resolved ASAP.
This experience is VERY frustrating, especially considering the premium cost of the XPS 15. I intentionally purchased a top-of-line laptop and fully expect it to be able to at least drive a second monitor with the super magical Thunderbolt 3 port. I am seriously considering returning the device and looking elsewhere.