XPS 13 9370 - How many external mointors at which resolution?

@InvisibleShadowGhost  the Intel GPU can run up to three simultaneous independent displays each at up to 4K resolution.  And in fact the GPU even allows all 3 displays to be external if you have a way to connect them that way AND you're willing to disable the built-in panel while using triple external displays.  (Note: Linux does not support disabling the built-in display, so even if you don't use it, it counts as an active display, limiting your external displays to 2.)

Anyhow, yes you can absolutely run dual external QHD displays.  I was doing that on a much older XPS 15 9530.  In terms of exactly how to connect them, you have multiple options:

- A Thunderbolt dock like the WD19TB
- A Thunderbolt 3 to Dual DisplayPort or Dual HDMI adapter
- DisplayPort daisy-chaining, i.e. use a USB-C to DisplayPort cable to connect to Display #1, and then connect the DisplayPort output on Display #1 to the DisplayPort input on Display #2.  This of course requires that you have at least one display that has that type of output to set up a daisy chain and that you be using DisplayPort signalling along the entire chain.  You cannot use HDMI or DVI adapters along the way.

Hopefully this helps!

@InvisibleShadowGhost  I just noticed the 144 Hz refresh rate.  First, I'm not sure Intel GPUs support 144 Hz in the first place. But if they do, I'm not sure dual QHD at 144 Hz would be manageable within the bandwidth limits of Thunderbolt 3.  It definitely would not work via DisplayPort daisy-chaining, since that only taps into a single DisplayPort link (4x HBR2 lanes), whereas Thunderbolt 3 taps into dual DisplayPort links.

I do know that Thunderbolt 3 has the bandwidth to handle dual 4K at 60 Hz, and QHD is slightly less than half the total pixels of 4K, so in theory running dual QHD at 120 Hz should be fine since that's slightly less bandwidth than dual 4K 60 Hz -- again assuming the Intel GPU supports 120 Hz to begin with.  But 144 Hz might be too much, and unfortunately documentation discussing support for relatively "niche" display setups such as very high refresh rates and ultrawide resolutions is tough to find.

Thanks for your response!

Well, I just assumed that it supports 144hz and thought I have read this somewhere. But that it something I should find out...

Anyway, 2 * 2560x1440@120Hz would be perfectly fine as well.

@InvisibleShadowGhost  happy to help! I seem to remember a discussion here where someone found that Intel GPUs will support 120 Hz, but I believe they found that 144 Hz was not available even though they were using a 144 Hz display and had it connected in a way that bandwidth would not have been an issue. But I’m just working from memory there. Anyhow, a Thunderbolt dock or Thunderbolt to dual DIsplayPort adapter would be your most convenient and functional option here.

The other option would be to direct connect each display using a pair of USB-C to DisplayPort cables. That would be less expensive but it would also be less convenient because you’d have two display cables connected directly and you’d also have no ports left if you also wanted to connect a charger. Or actually there are USB-C to DP cables that have an inline USB-C power input, so you’d connect the laptop charger to one of those cables so that it would handle video output and power input through one cable. That setup would only require 2 total cables directly connected to the system (which you’d have anyway unless you went with a full dock) and would still likely be less expensive. I’ve included a link to that type of cable below, and of course you’d only need one like this. The other could be a regular USB-C to DP cable.

https://www.amazon.com/dp/B0746NM5H9/

@InvisibleShadowGhost  no, the WD15 will not work.  The WD15 can only support dual displays up to 1920x1200 at 60 Hz, or a single 2560x1600 display at 60 Hz (or a single 4K 30 Hz display).  This is due to bandwidth limitations of regular USB-C when the link is also set up to support carrying USB 3.x data, as it would be when connected to a WD15 in order to allow other functions of the dock to operate, such as USB ports, audio, Ethernet, etc. The WD19TB I suggested above uses Thunderbolt 3, which allows it to tap into 4x more display bandwidth, which is how dual 4K 60 Hz is possible (and therefore from a bandwidth perspective dual QHD 120 Hz would also be possible, although again I don't know if there might be other limitations there.)

That's good to know that 120Hz should work. If you find the other thread with the described behavior, I would be happy if you could send me the link

I already have the WD15 dock and used it to connect two external monitors in the past. This should work just fine, right?

@InvisibleShadowGhost  I found one thread here where a user was able to run 120 Hz on an XPS 15 9560, which is a generation older than your XPS 13 9370, and even though the XPS 15 has an NVIDIA GPU, the Intel GPU still has direct control of the display outputs.  That user had that option while running a display resolution he didn't want to be running, but that was a separate issue.  I also found other, older threads where I'd mentioned seeing confirmation elsewhere that Intel GPUs can run at least 120 Hz, but at the moment I can't seem to find those sources.  Anyhow, it seems that 120 Hz itself doesn't seem to be a problem.

@jphughanThanks again for your responses.

That the WD15 won't work is unfortunate, but obviously makes sense. Thanks for the heads up here! Also thanks for the link to the other thread where the user reported the avalilability of 120Hz.

So the result is that I have to try it out somehow. I will go to a shop at some point when this is possible again and report back here what my findings are

Hi - do you know how I'd practically go about disabling the internal display so that Windows 10 Display will then detect and use my third external monitor? It'd have to be reasonably easy to do and undo as I do use my XPS on the move. I tried simply selecting 'disconnect this display in the Windows 10 Display box but that didn't cause the system to recognise the third external screen... Thanks!

@Bartleby1848  Open Windows Display Settings, make sure all displays are in Extend mode (no mirrors anywhere), and then you should be able to simply click Identify to see the ID of your built-in display, click that display in the multi-display graphic at the top of the interface, then scroll down and set it to "Disconnect this display".  I do this pretty frequently to run 3 external displays from systems with an Intel GPU.  If that doesn't work, you can try doing the same sort of thing in Intel HD Graphics Control Panel (or Command Center, depending on your driver version).  If that still doesn't work, can you provide more detail about exactly which displays you're using and how you've got everything connected?