Connect Latitude 5480 with docking station to External Monitors

@jgs04001  fyi you should really check the exact dock model you have when asking technical questions like this, because the answers sometimes depend on knowing the exact equipment you're using.  The dock model should be printed on the underside of the dock.  But if you're using the WD15, that model can run dual displays only up to 1920x1200, or a single display up to 2560x1600.  It can't run even a single 4K display unless you're ok with only 30 Hz refresh rate, but most people consider that unacceptable.  This is all indicated on the WD15's product page, user manual, and FAQ document, and it stems from limitations around USB-C bandwidth when used in docking station mode.  I wrote a detailed summary of the various USB-C and Thunderbolt 3 operating modes, as well as their impact on available display setups, in this thread if you're curious.

If you want to run dual 4K displays at the standard 60 Hz refresh rate, then if your particular Latitude 5480 build includes Thunderbolt 3, which is optional on that model, your best option is to use a Thunderbolt 3 dock like the Dell WD19TB, or its predecessor the Dell TB16.  If you do NOT have Thunderbolt 3, then your system doesn't have a way to provide enough display bandwidth to run dual 4K displays natively from the GPU, in which case your only option would be a dock that uses DisplayLink compression technology instead.  The Dell D6000 is one such dock, but be aware that DisplayLink has some potentially significant drawbacks.  I've written about those in this thread, specifically the post marked as the answer.  Note that even though the question was about gaming, my answer applied more broadly.  Those drawbacks may or may not be relevant to your use case, but they're worth knowing about before you commit.

If you don't have Thunderbolt 3 and DisplayLink won't work for you, then unfortunately you'd need to get a different system if you want to run those two displays at their native resolution.

But no matter what you do, fyi Intel GPUs support 3 simultaneous independent displays, so if you had appropriate equipment, you would be able to keep the built-in display running alongside your 2 external displays if desired.

@jgs04001  one note in addition to the above.  This is mentioned in the WD19TB manual, but if you go with that dock and want to run dual 4K displays, one of the displays has to be connected to the "upstream" Thunderbolt port on the back of the dock near the very edge (not the USB-C port right next to the HDMI port).  You'll need a USB-C to DisplayPort cable for that.  The reason has to do with the way the dock allocates display bandwidth from the attached system.  All of the other outputs share a single DisplayPort 1.2 channel, which is enough to run a single 4K 60 Hz display.  The other DisplayPort 1.2 channel required to run a second 4K display is allocated to that "upstream" Thunderbolt port.

My 5480 should connect to my WD15 docking station with dual monitors correct?

@LarkinLee  yes, as long as the resolution of those displays are no higher than 1920x1200 each.  If you want to use a 2560x1440 display, you'd only be able to use one through the WD15.  If you try to connect two displays when one of them has a higher resolution than 1920x1200, you will likely end up with one or both displays running a lower than native resolution due to insufficient video bandwidth.

@jphughan Well, it works - I have both monitors - part of it was a new driver issue for the WD15 which I pulled down from the site. One thing I am very interested in is being able to shut my laptop cover and continue to work on my monitors. When I shut the cover the whole deal powers down. My other 5480 did not do this.

I would also like to be able to just plug in the usb C and start working, but currently I have to open the monitor to get everything working. Any tips?

So, the BIOS upgrade seems to be incompatible with my latitiude 5480 windows 10 64 bit

Now what. 

Man this seems like a lot of BS.

Many thanks, and no - the power button on the WD15 does not work when I press it with the laptop closed.

I've updated the firmware but not BIOS. Where can I find that for the WD15?

@LarkinLeefor the lid close issue, you have two options:

Option #1: In your Power Settings, set the lid close action to "Do Nothing" rather than the default "Sleep".  But if you do this, remember that you can't just close your lid before you stuff your laptop in a bag and count on it going to sleep.  You'd have to put it to sleep manually; a quick way to do that is to right-click the Start button or press WinKey+X, then go to "Shut down or sign out > Sleep".  I use this setup because I seldom use Sleep.

Option #2: If you don't want to change the lid close action, then you'll have to close your lid and then press the dock's Power button to wake the system back up while the lid remains closed.

The Option #2 I described above sort of hints at the answer to your second question about how to just plug in and start working.  You can already do that.  Connect your system to the dock, and then press the Power button on the dock to wake it up or power it on.  You might have to wait a second or so after connecting before that button works, but the Power button on the dock is meant to work identically to the system's built-in Power button, just like the Power buttons on "legacy" docking stations.  You can even press and hold that Power button to force your system to power off, for example.  If that isn't working, make sure your system's BIOS and the WD15's firmware are both updated.  (This is all mentioned in the WD15's manual available on support.dell.com, by the way.)

@LarkinLee  you can find WD15 firmware by going to support.dell.com and searching WD15 as your product model, then going to its Drivers & Downloads page.  Direct link to that is here, and you'll find the firmware at the bottom of the list.

As for the 5480 BIOS update, I don't have a Latitude 5480 specifically, but I've never seen that behavior on any system, not even my similar Latitude 7480.  Are you sure you downloaded the right file?  The latest BIOS release for the Latitude 5480 as of this writing is here.

Thank you for all of your help. I've got it all working, I just have to remember to put my computer to sleep at the end of the day or it stays on all night.

Much appreciated!