XPS 13 dual monitor setup help

@marcass  since you only have one USB-C port, then if you want to run multiple displays from it without incurring the cost of a full docking station, your best bet would be to get either a USB-C DisplayPort MST hub or else get a Thunderbolt 3 to Dual DispayPort adapter.  They look similar, but the latter will be more expensive because it will allow you to tap into twice as much video bandwidth as the former, which might be important depending on the resolution(s) of the displays you want to run.  You didn't mention what type of display you're planning to buy or even the resolution of your current display. As a general note, when asking about technical questions like this, it helps to provide technical information.

The only other option would be to buy a display that supports DisplayPort daisy-chaining, but that won't work unless you can use DisplayPort the whole way, and since you mentioned that your current display only allows DVI and VGA (not serial), then that's off the table.  And speaking of that display, if it does in fact support DVI, getting a USB-C to DVI cable/adapter would have given you better image quality than using ancient VGA, because VGA is an analog signal, whereas all other display connection types these days are digital.  Or you might have had an easier time finding a USB-C to HDMI adapter dongle and then an HDMI to DVI cable.

But if you go with either the USB-C DisplayPort MST hub or Thunderbolt 3 to Dual DisplayPort adapter, then from there for best results you'd want to get an active DisplayPort to DVI cable/adapter to connect to your existing BenQ display.  They're slightly more expensive than the much more common passive DisplayPort to DVI cables/adapters, but most MST hubs and TB3 to Dual DP adapters won't allow using passive cables to convert DP to DVI.  And then ideally for your new display you'd just make sure it had a DisplayPort input, in which case you could use a simple DisplayPort cable.

EDIT: Somehow missed the reference to the 9360 model. Updated my post.

Thank you for the very prompt response, and apologies if I neglected to include the technical spec's.

I am not certain of the specific model except for the 9360 number, where would I find such details.  I can tell you the machine is 3 years old.  I have only 1 USB-C port, not 2, so much of what you said was relevant to the port I have.

You refer to TB3 and USB-C, and from looking at the plug that fits, they seem to be the same.  can you explain the difference (if any) and what I am likely to have.  Not sure how to give you the technical spec.... sorry!

Given my restricting factor is cost, would you be able to link to some examples of the USB-C to Displayport hub, and the TB3 to Dual Display port adapter please?

A link to an Active Displayport to DVI cable too would be really useful.

Thank you again for your help!

@marcass  I just needed to know the 9360 model that you provided.  I just missed it at first, sorry about that.  Knowing the resolution of the display you're currently using and the resolution you'd like to run on the additional display you'll be purchasing would be useful.  Or the general information I posted in my second reply might help you decide which product to go with.

USB-C and TB3 both use a USB-C connector.  TB3 is basically a superset of USB-C functionality, but in order to use a TB3 peripheral, you need a system whose USB-C port supports Thunderbolt 3.  The XPS 13 9360 comes standard with Thunderbolt 3 capabilities on its USB-C port, so you'd be fine using such a peripheral.

In terms of recommendations, I'm not sure what part of the world you live in, but if you search online retailers for something like "Plugable Thunderbolt 3 to Dual DisplayPort adapter", or replace "Plugable" with one of the other vendors I mentioned, you should be able to find them.  I'm in the US and Amazon carries those adapters from the vendors I mentioned.  And if you want the MST hub, just search "StarTech USB-C DisplayPort MST hub", for example.  Same for "Active DisplayPort to DVI cable".  For the cable, make sure the product description specifically mentions that it's active.  If you look for a cable that mentions support for AMD EyeFinity, that will be an active cable since EyeFinity requires it, even though I realize you won't be using an active cable for that specific purpose.  Here is one such example from the Amazon US site.  Good luck!

@marcass  happy to help, and thanks for the kind words!

Those will work, although if you want to connect to an HDMI input, you would need an active DP to HDMI cable or dongle.  If you want to avoid that, you might want to find a Thunderbolt 3 to Dual HDMI 2.0 adapter. Those aren't quite as common, but Plugable actually does make one such adapter -- here is the Amazon UK link to it.  As you can see, it costs more.  That's likely due in part to the fact that it essentially has active DisplayPort to HDMI converter chips built in (since Thunderbolt 3 always sends a DisplayPort signal) and also partly because HDMI ports require the manufacturer to pay a royalty for every port they put onto a product, whereas DisplayPort is unencumbered.  However, an additional bonus of going that route would be that you could then use a standard HDMI to DVI adapter/cable to connect to your existing BenQ display, since HDMI and single-link DVI are identical signals at an electrical level.

However, there are some drawbacks to going with dual HDMI rather than dual DisplayPort.  The first is that some displays on the market will only accept their maximum resolution over DisplayPort even if they also offer an HDMI input.  The reason is that at any given time, the current DisplayPort standard has always supported higher resolution than the current HDMI standard, so displays manufactured during a time when the current HDMI standard didn't support the resolution of the display would only be able to accept some lower resolution signal on their HDMI input, usually 1080p.  And second, some displays, especially lower-end displays, might offer only DisplayPort without offering HDMI at all -- again likely due to the royalty associated with HDMI -- and you cannot convert an HDMI source signal to DisplayPort; you can only use DisplayPort to HDMI cables/adapters to go from a DisplayPort source signal to HDMI.

So, bottom line: Starting with DisplayPort outputs gives you the greatest flexibility, since with the correct cables/adapters, you can use DisplayPort outputs to feed a DisplayPort, HDMI, DVI, or VGA input.  However, if your main concern is a DVI display and HDMI TVs, and you make sure that your next display includes an HDMI input that will allow the display to be run at its maximum resolution, then a TB3 to Dual HDMI 2.0 adapter might be a better choice in your particular case.

Your reply is so helpful, I'm sure I'm not the first to tell you this as a quality!  I'm in the UK.

I shall take your advice and get a TB3 to DP and propose this

I shall get this for the Active DVI cable.

If I wanted to connect to 2 TV's on HDMI, would a simple converter cable for DP to HDMI work?

Thank you

Oh by the way, one last thing. Make sure your XPS 13 BIOS, Thunderbolt 3 controller firmware, and Thunderbolt 3 software/drivers are all up to date.  If you have Dell Update installed on your system, you should be able to simply run that to get those updates if you don't already have them. Otherwise, you can find them at support.dell.com by just searching for XPS 13 9360 and then going to the Drivers & Downloads page. Thunderbolt required a lot of BIOS, firmware, and software updates before things tended to work together fairly reliably, so if you're behind on those items and don't update, you might experience some issues trying to get this setup working.

Excellent, thanks for reporting back!

@jphughan  

I think you missed my earlier message.....when I close the lid on my laptop all the screens go off, and the windows settings are correct to show that closing the lid does nothing.  can you help with this too please?  thank you

@marcass  sorry, I was apparently reading this thread too early in the morning.  Setting the Lid Close Action to "Do Nothing" just means don't go to sleep, hibernate, etc.  The built-in display will always power off when the lid is closed regardless of that setting.  However, I've never heard of closing the lid blanking all attached displays.  I'm curious about two things:

- Is the PC just disabling the external displays or actually going to sleep or something?  To test this, try playing some music and closing your lid.  Does the music continue playing?

- While your lid is open, go to Windows Display Settings, select your built-in display, scroll down to "Multiple Displays", and set that display to "Disconnect this display" so that it will be disabled even while the lid is open.  Now try closing the lid.  Do your external displays stay active now?  (Note: Windows will always automatically re-enable the built-in display if there are no other attached displays, so there's no risk to setting your built-in display to disconnected while the lid is open.)