I found this link:

https://www.dell.com/support/article/us/en/04/sln305150/some-systems-with-usb-type-c-port-lack-a-thunderbolt-3-controller

It says:

"Systems that have optional Thunderbolt 3 capability will have a USB/Thunderbolt configuration option listed in the BIOS regardless of having a Thunderbolt 3 option installed."

So, although the options are NOT greyed out in my BIOS (I haven't checked my wife's yet), that doesn't necessarily mean that the Thunderbolt 3 option is "installed". How can I tell if it is actually installed?

Also, this doesn't say anything about how to tell the difference between Thunderbolt 2 and 3.

Thunderbolt 3 aside, what about the E-Port Plus II dock? Again, I'm not sure if my wife's Latitude 7480 has a E-Port connector, but mine does. Regardless, I found the following:

https://www.dell.com/support/article/us/en/04/sln300546/e-port-plus-and-4k-displays?lang=en

This says:

"The DisplayPort Video ports will only display DUAL 4k x 2k resolution @ 30 Hz refresh rate on MST equipped systems.

If your system is equipped with Discrete NVidia or AMD graphics, then dual 4k x 2k displays @ 60 Hz can be achieved using the E-Port Plus dock."

My laptop has switchable AMD FirePro W5130M graphics, but I suspect my wife's only has Intel integrated (not sure which version). It is unclear whether or not the 2nd statement supersedes the 1st (i.e. does having Discrete AMD graphics allow 4k@60Hz regardless of whether or not the system has MST).

How can I even tell if our systems have MST or not?

Thanks!

What about my questions regarding the E-Port Plus II?

Actually, I suspect that my wife's Latitude 7480 DOES have an E-Port connector on the bottom because some of my work colleagues have 7470s which apparently DO have the connector. Unless of course they removed it for the 7480...

@TomLXXVIII, Thank you for the question.

For your 3510: Since your 3510 has the Thunderbolt logo you can use the TB16 Docking Station: https://www.dell.com/en-us/shop/dell-business-thunderbolt-dock-tb16-with-240w-adapter/apd/452-bcnu/p...

As you will see in the following link, the Dock Supports 2 Displays with 4k@60Hz: https://www.dell.com/support/article/us/en/04/sln301105/dell-thunderbolt-dock-tb16-information-and-s...

For your 7480: You can check in device manager, under Chipset, to see if you have Thunderbolt. You can also use this link to check for Thunderbolt: https://www.dell.com/support/article/us/en/04/sln305150/some-systems-with-usb-type-c-port-lack-a-thu...

Thunderbolt 1 and Thunderbolt 2 uses miniDP

Thunderbolt 3 uses USB Type-C connector

If your 7480 does not have the Thunderbolt logo, you'd be looking into the WD15 docking Station, which does support a single display @4k@30Hz, but not at 60Hz.

Here's a Specs link to the WD15:<ADMIN NOTE: Broken link has been removed from this post by Dell>

 You can find the WD15 here: https://www.dell.com/en-us/work/shop/dell-business-dock-wd15-with-180w-adapter-with-dib-mdp-to-dp-ca... Hope that helps you out.

@TomLXXVIII  you should definitely determine whether your systems have Thunderbolt 3, because Thunderbolt 3 makes 4x more display bandwidth available than USB-C with those systems.  With regular USB-C on those systems, you'd be limited to dual displays at 1920x1200 each, whereas Thunderbolt 3 allows dual displays up to 4K 60 Hz.  In terms of how to tell whether you have Thunderbolt 3, one way would be to go to the BIOS Setup interfaces of each system and check the Thunderbolt Configuration section.  If all of the options are grayed out, you don't have it.  If you can toggle options, you do.

If it turns out that one system has Thunderbolt and the other doesn't, your best dock option would arguably be the WD19TB, because that dock will take advantage of Thunderbolt 3 when connected to a system that supports it, but unlike most Thunderbolt peripherals on the market, it's also backward compatible with regular USB-C systems (at reduced functionality equivalent to the regular WD19).  That backward compatibility comes courtesy of the relatively new Intel Titan Ridge controller chip.  Otherwise, if you got a regular USB-C dock like the WD19, it wouldn't make full use of Thunderbolt systems, and if you got pretty much any other Thunderbolt dock on the market right now, including the older TB16, it wouldn't work at all with regular USB-C systems.

The manual for the WD19TB that you can find on support.dell.com will tell you the maximum available resolutions.  Note that both of your systems are HBR2/DisplayPort 1.2 systems.

@TomLXXVIII  yes, even systems that don’t have Thunderbolt will have that section of BIOS settings with those options visible — but as I said, those systems will have all of those options grayed out, whereas they will be configurable on systems that actually have Thunderbolt. I’m speaking from direct experience with both types of systems here.

Thunderbolt 1 and 2 only use a Mini-DisplayPort connector, and Thunderbolt 3 only uses USB-C. To my knowledge Dell never made any TB1 or TB2 systems. I think the only laptop systems that ever had that were Apple systems, and then there were some Mac and PC desktop systems/motherboards that had it.

The Latitude 7480 does not have an E-Port underside connector. The E7470 does. The key is the “E” prefix that exists in the latter’s model name and that’s missing on the former’s. That prefix was always used for Latitude systems to indicate the generation of underside docking station connector they used, so before the Latitude E series systems there were systems like the Latitude D820 that used a D-Port Dock. Some Precision systems also had D- and E-Dock connectors, but for some reason they never used that prefix system in their model names.

The resolution note you found applies to systems when sending video through an E-Dock connector. It does not apply to Thunderbolt 3 or even regular USB-C connections where the display setup limits that I mentioned above (and that are also listed in the manuals of those docking stations) would apply.

@DELL-Justin C  the Thunderbolt controller only appears in Device Manager when an actual Thunderbolt device is connected (not just a USB-C device) and at least on my Thunderbolt-equipped 7480, it appears in the System Devices section, not Chipset.

So, assuming both systems have Thunderbolt 3, the last question is whether or not the graphics controller on each laptop can actually drive dual 4k@60Hz monitors. Mine has Intel HD 530 AND AMD FirePro W5130M. Not sure exactly what she has, but I'm guessing it is Intel HD 620 since she has a gen 7 Intel CPU.

@TomLXXVIII  Intel GPUs since at least the HD 4600, included in Core 4th Gen CPUs and older than both of the Intel GPUs in your systems, have supported 3 simultaneous independent displays at up to 4K 60 Hz each as long as the necessary display outputs to actually run that setup have been present.  Dell's Thunderbolt 3 systems all have two DisplayPort 1.2 interfaces wired from the GPU to the Thunderbolt 3 controller, which allows dual 4K 60 Hz displays to be driven from that port.

And while it won't be relevant to your combination of systems, if you're curious, the MST limitation you referred to a while ago with E-Dock systems didn't refer to MST support within the system, which is a common and useful capability.  It referred to systems that have an Intel GPU and use an internal MST controller in order to drive dual dock displays from a single DisplayPort 1.2 interface coming off the GPU.  That's why you're limited to 4K 30 Hz when running two displays in such systems.  Basically, a 4K 60 Hz display requires almost an entire DisplayPort 1.2 interface of bandwidth.  In systems that have an E-Dock connector and a discrete GPU, the dGPU has two DisplayPort 1.2 interfaces wired to the dock, which is why they can run dual 4K 60 Hz displays.  But E-Dock systems that only have an Intel GPU run the entire dock from a single DisplayPort 1.2 interface.  DisplayPort MST is a technology that allows multiple independent displays to be driven from a single DisplayPort output.  So that means such systems can still run dual displays through an E-Dock, but there's still only one interface's worth of bandwidth, which means either a single 4K 60 Hz display or dual 4K 30 Hz displays.  But again, that's not relevant to your case because your 7480 doesn't even have that E-Dock connector and Thunderbolt 3 is wired differently.