XPS 15 9500, 2 4K monitors?

Yes, it will drive 2 4k monitors on 60hz, you don't even need any additional accesories, you can connect them through usb-c (if your monitors have such connector) or through displayport to usb-c adapter cables. 
There are also 2xdisplayport to usb-c adapters (look under the name "dual displayport to usb c" if you wanna save one tb3 port. 
You can also go with some thunderbolt 3 docking station.  

Agreed with the other, with only the clarification that you want a thunderbolt3 to dual display port adapter. I dont think a USB-C (without thunderbolt3) has the bandwidth of two 4k@60hz.

something like the link below should work. the adapter is not cheap, so you might be better off putting a little bit more money and get a Tb3 dock with two display ports and other perks.

 sorry, I am new to this platform it seems links are blocked. Amazon sells one Sabrent Thunderbolt 3 to dual display adapter, that cost about $80.

@unknown1950 Just to confirm, make sure you're using the Type-C port at the edge of the dock, not the Type-C port near the HDMI output.  If you've already confirmed that, there are some USB-C to HDMI adapters that don't support 4K 60 Hz, but the first test to run would be to see whether you can get 4K 60 Hz on each display through its current cabling when it is the only display connected.  Does that work?  If so, then the adapter is not your issue.  In that case, I've read about some issues with certain Dell systems and the WD19TB when running dual 4K 60 Hz.  The XPS 13 9300 had some issues at least early on; not sure whether those were fixed.  So make sure your BIOS is current and that the WD19TB firmware is current.  If even that doesn't resolve it, user decker12 on this forum supports a business that has a lot of these and uses them with dual 4K 60 Hz displays, and he's found that the most reliable connection is to use the two USB-C ports with USB-C to DisplayPort cables.  The system outputs DisplayPort over TB3 natively, which means the dock's USB-C outputs also output DisplayPort natively.  USB-C to HDMI adapters have to incorporate active signal converter chips to switch that over to HDMI, and I've also seen multiple cases here where users had an adapter like that and found that it worked with one system and not another, even though it should have worked with both.  And in all of those cases, the fix was just to try another brand of adapter, which ended up working with both.  Complexity can decrease reliability.  And just fyi, since your displays support G-Sync, you'd have to use DisplayPort in order to use G-Sync anyway -- but that's irrelevant in this specific case because the display outputs on the XPS 15 9500 are wired to the Intel GPU rather than the NVIDIA GPU, which means you can't run G-Sync no matter what.

Hi ,

thanks for fast reply.

Yes, I'm using Type-C port at the edge of the dock. I cant get 4k display at 60Hz when using Type C - port -> HDMI. However, I can get 4k on the DP and HDMI port no matter which display I connect. So, so far it seems to me like the adapter could be issue. I will try some of your suggestions and keep you updated. 

Thanks

@unknown1950 Ok, as one last test, try connecting the USB-C to HDMI adapter to the USB-C port near the HDMI output while the other display is completely disconnected.  If you still can't get 4K 60 Hz even in that setup, then yes the adapter is the likely issue.  If you replace it, I'd suggest going USB-C to DisplayPort instead, simply to end up with a simpler adapter.

Hi,

so in the end, I bought right adapter (ucb c to display port) that supports 4k 60Hz. The one I got with the laptop obviously doesn't support 4k 60Hz. 

My configuration is Dell XPS 15 9500 connected on the docking station wd19tb. One monitor is connected USB C to DisplayPort. USB C is located on the edge of docking station. The other monitor HDMI to HDMI.

60hz 4k on both of them.

Thanks for support. I hope my solution will help someone.

Cheers

@unknown1950  Ah, you should have mentioned that you were previously using the USB-C to HDMI adapter that came with the system.  That adapter DOES support 4K 60 Hz, but only when used with a system that supports DisplayPort 1.4/HBR3.  The reason is that the adapter always configures the USB data path to support USB 3.x, and when you do that, your video bandwidth gets cut in half.  A half-bandwidth DP 1.4/HBR3 link is still enough to run 4K 60 Hz, but the XPS 15 9500 only supports DP 1.2/HBR2, and a half-bandwidth HBR2 link is only enough for 4K 30 Hz (or 1440p 60 Hz).  The only way to run 4K 60 Hz from an HBR2 system over regular USB-C (meaning without Thunderbolt) is to limit USB data speeds to USB 2.0.  It might have been nice if the adapter supported being configured for "4K 60 Hz + USB 2.0" or "4K 30 Hz + USB 3.x" given that the adapter is being bundled with HBR2 systems, but that isn't possible.

What about the WD19DC or WD19DCS since they both have even more power. Are those two ok two have two 2K or 4K displays on a Dell 15 9500?

@michaelbc  Power has no effect on display support. The power only affects the types of systems you can run properly from the dock. But the DC and DCS are designed for the Precision 7000 Series systems. The XPS 15 9500 does not need and will not benefit from the extra power those docks provide, and in fact when used with a system that doesn’t explicitly support using that dock in dual connector mode, it will operate like the regular WD19(S), not the WD19TB(S), which will significantly REDUCE the display setups you can run. To my knowledge, the only systems that explicitly support dual connector mode are those Precision 7000 systems. Other systems use it as a regular USB-C dock even if you can physically connect both connectors.

@jphughan WOW! Thanks for this awesome explanation. My two screens are Asus TUF Gaming VG27AQ HDR Gaming Monitor – 27 inch WQHD (2560x1440), IPS, 165Hz*, Extreme Low Motion Blur Sync, G-SYNC Compatible, Adaptive-Sync, 1ms (MPRT), HDR10. 

Will the WD19TB or WD19TBS support them into my XPS 15 9500?

@michaelbc  Also, be aware that if you go dual 4K, or actually any setup that involves a 4K display and anything else, then when you use the XPS 15 9500 with a WD19TB(S), you'll need to connect a 4K display to the downstream TB3 port at the edge of the dock -- not to be confused with the USB-C port near the HDMI output.  Use a USB-C to DisplayPort cable if needed.  The other display can be connected to any other output.  This requirement has to do with how the dock allocates video bandwidth.

@michaelbc  The WD19TB or WD19TBS, yes -- assuming when you say "2K" what you actually mean is QHD.  2K is a film resolution of 2048x1080, but when used in the consumer space it actually is meant to refer to the nearest and slightly LOWER resolution of 1920x1080, just like “4K” is a film resolution of 4096x2160 but when used in the consumer space refers to 3840x2160. But many people use “2K” incorrectly to mean 2560x1440, and the result is that it’s no longer clear what anybody is talking about when they say “2K”, which in turn makes the term worthless. By comparison, QHD and 1440p are both clearly 2560x1440. QHD is only one more character to type compared to 2K, but it adds a lot of disambiguation value, and that’s important when asking questions like this. For example, if I had assumed that you actually meant 1920x1080 when you said “2K”, then I could have given you a solution to run dual 1920x1080 displays from that system, but that of course wouldn’t have been what you wanted. Being clear is important in technical discussions.

Got it, then the only option is truly the WD19TB for an XPS 15 9500, in order to support two 2k/4k monitors, correct?