XPS

Last reply by 11-20-2019 Solved
Start a Discussion
2 Bronze
2 Bronze
21560

XPS 15 9570 - Use Dual Displays + Laptop Display in Extend Mode

I have an XPS 15 9570 with the  i7-8750H, 16GB RAM,  512GB SSD, NVIDIA® GeForce® GTX 1050Ti and 1080p screen. 

I'm interested in creating a setup where I can use two external monitors along with the laptop screen, in extended mode. I want this for productivity reasons, so I can have three different applications open on each screen. 

I want to be able to use two Dell P2418D monitors (see link below) as the external displays, running each external display at 1440p at 60Hz. 

Since the external monitor i'm interested in has a display port (version 1.2), I want to make use of the USB-C (Thunderbolt 3) port on the laptop. So basically a docking station with two display port outputs (each of which supports the 1440p at 60Hz), and some other useful ports like USB type A, type C etc. I don't necessarily need to charge the laptop through the USB-C port; I can use my regular charger for that. 

 

My questions are as follows:

  1. Is it possible for my laptop to run this setup?
  2. If yes, what docking stations do you recommend? 
  3. Is there any other advice?

 

Dell P2418D:

https://www.dell.com/en-us/shop/dell-24-monitor-p2418d/apd/210-amuh/monitors-monitor-accessories

 

PS: I'm new to using dual external displays in tandem with a laptop's display. However, I understand the basics of external display systems. 

Labels (3)
Replies (16)
20429


@ksrw395 wrote:

Many thanks again for the knowledge. 

 

I've decided to go for two of these 24" 1080p monitors, and daisy chain everything, similar to your setup. 

https://www.dell.com/en-us/shop/dell-24-usb-c-monitor-p2419hc/apd/210-aqco/monitors-monitor-accessor...

 

In the future I may look into the dock method. 

 


Nice choice!  Since that display model has a native USB-C inputs, you can use a regular USB-C cable to connect the XPS to Display #1, then use a regular DisplayPort cable to connect #1 to #2.  Also be aware that you might have to go into the settings on the display itself to enable DisplayPort 1.2 mode or DisplayPort MST mode in order to make daisy-chaining work.  On some Dell displays that option is disabled by default from the factory, and if you don't enable it, you'll only get mirroring rather than extend mode.


20434

Many thanks again for the knowledge. 

 

I've decided to go for two of these 24" 1080p monitors, and daisy chain everything, similar to your setup. 

https://www.dell.com/en-us/shop/dell-24-usb-c-monitor-p2419hc/apd/210-aqco/monitors-monitor-accessor...

 

In the future I may look into the dock method. 

 

20459


@ksrw395 wrote:

Thank you for your very detailed replies. 

 

You mentioned:


I can go into more detail on why trying to use multiple scale factors simultaneously is bad if you'd like

Can you please elaborate on this? 


@ksrw395  happy to help.  As for the part you quoted, I actually found an earlier post where I wrote about this.  Read the "Bluriness" section of this post for more info.


20474

Thank you for your very detailed replies. 

 

You mentioned:


I can go into more detail on why trying to use multiple scale factors simultaneously is bad if you'd like

Can you please elaborate on this? 

7 Plutonium
20484

@ksrw395  one more bit of advice in addition to my reply above: I'd really think twice about whether you want QHD resolution on a 24" display.  That creates a very high pixel density that might be tricky to work with without enabling display scaling.  Some Windows applications don't work with display scaling very well at all, but Windows itself can look very bad if you end up using multiple displays with different scale factors simultaneously.  If your built-in display is 1080p, I'm guessing you're not using any display scaling at all (i.e. 100% scaling), so if you plan to run that display and external displays simultaneously, you'll really want to choose external displays that won't require any display scaling either.  I can go into more detail on why trying to use multiple scale factors simultaneously is bad if you'd like, but suffice it to say you really want to avoid that.  QHD resolution is typically found on 27" displays, and in fact even that setup is higher pixel density than the common 24" 1080p setup.  Here are some numbers for context:

- Windows has always been designed to assume a baseline display density of 96 pixels per inch.  With that type of display and a 100% scale factor, something that's supposed to be 1" wide in the real world would appear 1" wide on the display.

 - A 24" 1080p display is 92 ppi, so things are a bit larger and grainier than that baseline.  A 27" 1080p display (rare, but they exist) is even worse at 82 ppi.

- A 24" 1440p display is 122 ppi, which is 33% more dense than "intended", so things at 100% scaling will be quite a bit smaller than normal, which could be uncomfortable to use.  By comparison, a 27" 1440p display is 109 ppi, i.e. 13.5% more dense, so things will still be a bit smaller (and sharper) than "intended", but it won't be nearly as bad.

- Your 15" 1080p display in the XPS 15 is 147 ppi, but that's common on laptops because people's faces tend to be much closer to their laptops than to their external displays, so it's not nearly as much of an issue there.

I personally run an XPS 15 with a 1080p display and dual 27" QHD displays and I think the setup is fantastic.  I can use 100% display scaling across the board, so I don't have any general scaling issues or any of the even worse multiple scale factor issues.  Since you specifically mentioned productivity, I'll give you one perk I discovered about 27" QHD displays:

If you have Windows set to 100% scaling, open Word, and set Word's zoom level to 105%, then your page as viewed in Word matches its real world size, and QHD resolution is enough to view two pages side-by-side in their entirety, including margins, in either portrait or landscape orientation (the pages in the document, not the display itself), and STILL have enough display area for the toolbars above and the status bars and Windows taskbar below.  The same is true in Adobe Acrobat, incidentally, although there I think you can set the pixel density of your display in the settings, so you can use 100% zoom and it corrects that internally.  QHD on a 25" display would still allow you to achieve these views because of its resolution, but because of its smaller size, the pages won't be real world size, so they might be harder to read.


7 Plutonium
20489

@ksrw395  if you want to run dual QHD, you either need to dedicate the USB-C port to video output (i.e. not use a conventional USB-C dock), use a Thunderbolt dock or adapter, or connect one of the displays via the built-in HDMI port.  There are various options in all of these categories.  I've summarized a few below:

- USB-C DisplayPort MST hub.  This will break your USB-C port out into multiple DisplayPort outputs.  Regular USB-C when dedicated entirely to video output has enough bandwidth for dual QHD.

- Thunderbolt 3 to Dual DisplayPort adapter.  This is a similar concept to the above but uses Thunderbolt rather than USB-C, which gives it access to twice as much video bandwidth.  So whereas the MST hub tops out at dual QHD, a Thunderbolt adapter would be able to run dual 4K 60 Hz in case you want some futureproofing.  But they're more expensive.

- Thunderbolt dock.  A regular USB-C dock (non-Thunderbolt) will NOT work because when the USB-C port is carrying both video and USB data, available display output gets cut in half, which means you'd only be able to run single QHD.  Since you're running an XPS 15 model, the only Thunderbolt docks that you can use if you want the system to be powered properly are some of Dell's own, because the XPS 15 requires 130W of power for optimal functionality, which is higher than the industry standard USB Power Delivery spec.  The best option at the moment for you would be the Dell WD19TB, their latest Thunderbolt dock.  Its predecessor is the TB16.  If you go the older route, you'll need to get the version with a 240W AC adapter, not the 180W adapter it was also available with.  The WD19TB only comes with a 180W adapter, but for that newer model, that still provides enough power to allow the dock to pass 130W through to the attached system.  A Thunderbolt dock would allow you to run dual displays up to 4K 60 Hz, or even triple QHD.  However, if you ever go with triple external displays, be aware that the Intel GPU only supports running three total simultaneous external displays, so you'd have to keep the laptop's built-in display disabled in that setup.  I realize you have an NVIDIA GPU in your system, but since I believe all outputs in that system are wired to the Intel GPU with the NVIDIA GPU operating in NVIDIA Optimus mode as a render-only device only when needed, you're subject to the Intel display's limits.  I've heard (but not confirmed) that on the 9570, unlike previous XPS 15s, the HDMI output is wired directly to the NVIDIA GPU, but that wouldn't help you in a dock setup because the built-in panel and anything attached via USB-C/TB3 would still be running from the Intel GPU.

- USB-C and HDMI.  Connect Display #1 via USB-C to DisplayPort cable, and Display #2 using a regular HDMI cable connected to the HDMI output.  But this obviously requires two cables attached to the system and doesn't provide any docking capability.

- DisplayPort daisy-chaining.  In this setup, you'd connect one display via USB-C to DisplayPort cable, and then connect Display #2 to Display #1 via DisplayPort cable, thereby running both displays via a single USB-C connection.  I use this setup with my Dell U2717D displays, but it doesn't look like the specific display you're looking at has a DisplayPort output to support daisy-chaining.

Hopefully this helps!


Latest Solutions
Top Contributor