Dell XPS 13 9350 - dual 4k@60hz with TBT3-DP2X - should it work?

Hi everybody, I have a Dell XPS 13 9350, i7, 8GB Ram, it has the build in “high res” display which is WQHD+ for the 9350 which is 3200 x 1800.

I’m now trying to get external monitors for this machine and I am aware of the various issues which have been reported when the model was introduced. I understand that one theoretical issue that the Thunderbolt 3 is only “2 pci lane” while newer XPS 13 models, I think from the 9370 onwards (the 9360 appears to be the same in this regard as the 9350), are “4 pci” lane.

Nevertheless, multiple sources state that the pluggable Thunderbolt 3 to DisplayPort adapter (TBT3-DP2X-83; NOT the HDMI version, I understand) is the way to go for the XPS 13 9350. Coincidently, I see the TBT3-DP2X-83 on Amazon at a price which I consider a very good deal.

Now my questions:

  • Am I able to do dual 4k at 60hz with 2 external 4k monitors (e.g. 2 x DELL UP2718Q Ultrasharp) with the TBT3-DP2X-83 using the “extend desktop” option (I am using windows by the way)? It’s important that I, of course, want to use “extend desktop”. I would not mind (let’s say: I could live with this) if I had to disable the internal monitor of the XPS 13 in order to achieve this. The evidence on the web whether this works or not does not appear to be conclusive. Some reviews on amazon seem to indicate that dual 4k @60hz on a Dell XPS13 with the TBT3-DP2X-83 works like a charm (I assume the internal display has been disabled in order to achieve this). Then, there are other sources which seem to point in the direction that it only works with mirroring the same desktop on both 4ks which of course would not help (particularly this source: https://gtrusted.com/how-to-get-4k60hz-resolutions-using-the-plugable-thunderbolt-3-dual-displayport-adapter-on-the-dell-xps-13-9350-laptop-and-lg-4k-27ud88-w-and-asus-pq321-4k-monitors appears to indicate that it works only if the two 4k monitors display the same desktop and do not extend). So, does it work? Do I have to disable the internal display for this?

  • As I have not bought the 2 x 4k displays yet (I was looking at refurbished Dells), would it be the safer option to go for 2 x QHD (2560×1440) instead? If going 2 QHD, could I possibly even use the internal display at the native 3200 x 1800 and have 2 x 2560×1440 at 60hz (using “extend desktop”)? If going 2 x 2560x1440 is the option which works better and has the added benefit of being able to use the internal display on top, I would seriously consider this route instead.

  • Further, is there a docking station from pluggable which does the same as the TBT3-DP2X83? If so, I would consider given the added comfort.

  • Lastly: As indicated, I understand there have been issues with the XPS 13 9350 and multi monitor setups. Would a better route be to either (i) use an ultrawide monitor instead or (ii) to sell the XPS 13 9350 and get a, say, XPS 13 9370 or some other notebook with 4 “pci” lanes from the Thunderbolt 3 port? I think a dual monitor set-up works better for me. Further, the ultra wide DELL U3818DW which provides pixel density comparable to QHD, is substantially more expensive than 2 x 27" WQHD (and, in my view, as said, less flexible). Selling the XPS 13 9350 and getting a XPS 13 9370 would be an option too, but I guess I loose around 200 to 300 bucks in doing so (and I might have the usual eBay trouble with the buyer and the seller).

Any help is extremely greatly appreciated!!!

Many thanks!!!

Hello and thank you for posting!

Thank you as well for the great detail you provided and the research you have already done that is much appreciated.

You cover a lot of ground, so I will do my best to respond to your points/questions in order:

  1. For your reference, Dell provides a knowledge base article that details the number of PCIe lanes routed to a system’s Thunderbolt 3 port here -> https://www.dell.com/support/article/us/en/19/qna44089/thunderbolt-3-40gbps-data-transfer-rate?lang=en To the best of our knowledge, the number of the PCIe lanes routed to the port does not indicate the number of displays supported via the port. Rather, this is determined by the number of DisplayPort video lanes routed internally from the system’s internal graphics adapter to the Thunderbolt 3 port. Most Dell systems route two DisplayPort lanes to the port, so two displays are typically supported. Dell does not provide a reference for this information unfortunately.

  2. Our TBT3-DP2X-83 adapter (https://plugable.com/products/tbt3-dp2x-83) will provide the ability to add up to two 4K@60Hz DisplayPort displays to the Dell XPS 13 9350 system. When using the DisplayPort version of the adapter, DisplayPort to DisplayPort video cables (cables with DisplayPort connector on both ends) must be used. Other video cables or adapters will not work.

You will not have to disable the laptop’s internal display while doing so. To expand further, the video capabilities of a Thunderbolt 3 host system are determined by the aforementioned internal DisplayPort video lane configuration and the capabilities of the system’s internal graphics adapter.

If I am not mistaken the 9350 model uses an Intel HD Graphics 520 graphics adapter which is capable of driving three total displays (one internal, two external). The reference for this information is taken from this link -> https://ark.intel.com/content/www/us/en/ark/products/88180/intel-core-i3-6100u-processor-3m-cache-2-30-ghz.html This is for the Core i3 processor used in the low-end version of the 9350, and provides the graphics adapter details inline.

The issues described within the Gtrusted link you provided would appear to have been specific to the displays in use, and would not appear to represent a limitation of the laptop or the Plugable adapter.

  1. Our Thunderbolt 3 Docking Station with charging known as the TBT3-UDV (https://plugable.com/products/tbt3-udv) would be an alternative to the TBT3-DP2X adapter. The TBT3-UDV dock will connect to one of the Thunderbolt 3 ports in your Dell laptop using the included 0.5 meter 40Gbps Thunderbolt 3 cable and will charge your system, allow for the connection of up to two 4K displays (lower resolutions also supported) as well as provide five additional USB 3.0 ports, a wired gigabit Ethernet port and combination audio jack.

The TBT3-UDV supports one DisplayPort display out of the box via its built-in DisplayPort video output. We also include a DisplayPort to HDMI adapter if your display only offers an HDMI input (DisplayPort or HDMI video cables not included).

A second display can be added to the dock using our either our USB-C to HDMI cable -> https://plugable.com/products/usbc-hdmi-cable or USB-C to DisplayPort cable -> https://plugable.com/products/usbc-dp, purchased separately and depending on your second monitor’s available inputs.

I made a short video that goes over the dock’s features and demonstrates how everything connects together that can help provide more context -> https://plugable.com/products/tbt3-udv#Demo

  1. We would not want to comment as to whether you should change your laptop model, as such a decision is personal and specific to the end user (appreciate your understanding in this regard).

Should you elect to proceed with a Plugable purchase and find that the Plugable products do not meet your needs, we do offer a 30-day no-hassle return policy for all products sold by Plugable and fulfilled by Amazon.

Apologies for the long post…please let us know if that information helps!

Bob
Plugable Technologies
www.plugable.com/support

Thank you so much Bob for this info! That sounds fantastic. I’ll keep you posted how it works out!

By the way: I also have the feeling that in the Gtrusted link the specific monitors in use appear to be a limiting factor. So, let’s see!

Hi Bob, sorry to bother you again and I am aware that without having the particular devices at hand you won’t be able to give a definitive answer: Could the XPS 13 9350 possibly run the LG 34WK95u-w with 5120 x 2160 @ 60Hz?

That monitor only has one DP in, so I guess there are chances that the TBT3-DP2X-83 can be used to run 3840 x 2160 of the LG at 60Hz via the DP in and the remaining 1240 x 2160 could possibly be run using a DP to HDMI cable and connecting to the HDMI in.

From what I understand just using an USB-C cable would probably not work - at least as the specs of the Intel HD 520 are exceeded.

Sounds like an educated guess?
Many thanks!

Hello and thank you for posting again!

As you suggest, we do not have the LG display you mention in our test lab so we cannot speak to its capabilities.

That said, our TBT3-DP2X adapter would not work in the scenario you describe due to several limiting factors. To expand further…

  • The Intel HD 520 GPU in the XPS 13 9350 laptop supports a single DisplayPort display at a maximum of resolution of 4096x2304@60Hz. It does not support the 5120x2160 resolution the LG display offers (also known as 5K).

  • In order to support a 5K signal at 60Hz refresh over a DisplayPort connection, the source device must support the DisplayPort 1.4 standard. The TBT3-DP2X supports only the earlier DisplayPort 1.2 standard.

  • HDR is not supported via DisplayPort 1.2 connections (this display has HDR support).

  • The TBT3-DP2X cannot ‘combine’ its two outputs into one display. There are some displays that can accept two separate physical DP inputs to reach 5K, but this is not one of them.

  • To obtain the maximum performance of this display, it appears it needs to be directly connected to the host system via Thunderbolt 3 cable. I do not know how the XPS 13 9350 laptop’s internal specifications/limitations would affect the performance of the display in that configuration.

In short, we cannot speak definitively to the behavior of the LG display with any system. Our TBT3-DP2X adapter is not a viable solution to connect this display to your (or any other) system.

Sorry we cannot be of more help…

Bob

That is extremely helpful - many thanks!

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