docking station for Precision 7520

@Journey to mars  That would be an E-Port docking connector, so you'd want either the E-Port or E-Port Plus.  The former allows you to run dual displays only if one of them is VGA.  The latter allows you to run dual digital displays (2x DVI and 2x DisplayPort outputs that can be used in any combination) plus a third VGA display if desired.  The Plus also has some legacy ports if you care about those.  Also be aware that there are first and second generation versions of each of those docks.  The second generation upgraded the two rear USB ports to USB 3.0 rather than USB 2.0 (the left side ports are still 2.0) and added support for DisplayPort 1.2 in order to support daisy chaining and displays that require more bandwidth such as 4K 60 Hz.  The way to tell the generations apart is that the rear USB ports on the second gen models are blue, whereas they're black on the first gen models.

The part I'm not sure about in your case though is what sort of power adapter you'll need when using a dock.  The E-Port docks normally come with a 130W power adapter when they'll be used with systems designed for 65-90W themselves (the dock needs some power to use for itself), but a 7520 would use a higher wattage power adapter even when the adapter was plugged directly into the system.  Some quick Googling suggests that you want a 240W power supply for the dock when you'll be docking a Precision 7520, which sounds right if you have a 180W power supply just for the system, but I'm not independently sure of that.

If you can, forget about the Eport + dock. It's old. 

In case you decide to get one be aware that the monitor outputs are paired. 

The DVI output is the same as the DP output underneath, so if you're using one DVI and one DP, make certain not to pick two ports above each other. Just a little gotcha, there. 

but homestly, get a more modern dock, such as the WD19DC(Dual USB C) because I believe that computer has dual USB C/Thunderbolt ports on the lefthand side. 

TB18 is also an option(no it's not, it's a piece of flaming minotaur droppings, but it must be remembered... ) and possibly a WD19TB ?

Best thing is the WD19DC comes with a 240W PSU.  

The WD19DC works with any computer that supports 'Displayport over USB C' Any that doesn't will get a reduced experience. 

I have also a Dell Precision 7520 and I am searching the right docking station.

The 7520 has only one USB-C/TB3 connector, so the dual USB C (WD19DC) didn't work.

After some research I found an interesting document about the compatibility of the Dell docking stations. You can find the document with the following Link:

https://www.dellemc.com/resources/de-de/asset/data-sheets/products/electronics-accessories/dell_docking_compatibility_guide.pdf

Summary:

The Dell docking stations WD19-130W, WD19-180W, WD19TB and WD19DC can't power your System if you have an Precision 7520. If you have one of theese docking stations you need to use the extern power adapter of the Notebook.

My question:

Can an E-Port II Plus docking station power my System (Precision 7520)? So that I didn't need to use my extern power adapter?

@Joel28  Yes an E-Port dock will adequately power a Precision 7520, as long as you connect a power supply of the appropriate wattage to the E-Port dock.  Those docks aren't constrained by industry standards like USB Power Delivery and their limitations.  Dell already stretched that spec by pushing 130W over USB-C/TB3, but they still had to resort to dual connectors to run more than that.  The E-Port dock doesn't have those issues since they were designed to support Precision systems in the first place.  The catch is that I'm not sure what the correct E-Port power supply wattage is for a Precision 7520.  Given that the system itself is designed for a 180W power source, the correct dock power supply is probably 240W.  Again I'm not sure, but the reason I think that's right is because dock power supplies typically have outputs above what the system requires since the dock needs some power to run its internal electronics and power any USB peripherals you might plug into it.  I doubt it needs an extra 60W over what it's providing to the system, but Dell has some standard power supply wattages, so if they need more than 180W, they'd just move to their next size up rather than creating yet another type of power supply with the exact required wattage.

Note that if you're buying used, many retailers will sell you only a docking station unit, i.e. without the power supply, and then you can separately buy a Dell 240W power supply, rather than having to find an entire docking station "assembly" that includes both the dock unit and the power supply as a single package.

@jphughan Thank you for your prompt reply.

I did some research about the compatibility of the Precision 7520 and an E-Port dock.

It looks like there are some restriciton. If the Precision 7520 has integrated graphics some ports of the docking station don't work.

The following links describe the restricition.

https://www.dell.com/support/article/de-ch/sln303940/certain-ports-are-not-functional-when-docked-with-precision-7520-7720-uma-graphics-config?lang=en

https://www.reddit.com/r/Dell/comments/8i44jb/precision_7520_docking_station/

My Precision 7520 has an integrated "Intel (R) HD Graphics P630". But if the informations of dell (see first link above) are right, I should be able to use some of the Ports of the E-Port dock.

If I am right, for the "E-port + II" I should be able to use 1x DisplayPort, 1x DVI and 1x VGA. So it should be possible to use 2x Monitors.

What do you think about that?

@Joel28 I hadn’t seen that, but based on that KB article, it appears that if you want to run two displays, you’ll need an E-Port Plus or E-Port II Plus, not an E-Port II. The difference between the original E-Port docks and the E-Port II versions is that the latter adds USB 3.0 and support for DP 1.2 rather than 1.1. But according to that KB, the only video output port that works on the regular E-Port is DVI. By comparison, the Plus dock allows DVI and DisplayPort. However, the DVI and DP ports that work are part of the same “bank” on the dock, which means they can’t be used together. So the only way to run two displays would be to run them both via that single DisplayPort output, either by using a daisy chain if your displays support that or by using an MST hub. This also means that your display setup will need to fall within the limitations of a DP 1.2 interface, which means you’ll only be able to run dual displays up to QHD/1440p each. And it also means you’ll definitely want an E-Port II Plus, not a first-gen E-Port Plus, in order to gain DP 1.2 output support, since that’s required for setting up a daisy chain or using an MST hub.

@Joel28  One quick addition to what I just posted. Are you sure that your system has ONLY the integrated Intel Graphics? Every Precision 7520 has integrated graphics, but the KB applies to systems that have ONLY that GPU and no discrete GPU at all.

@Joel28  Ok, one last thing. VGA is marked as NOT working on both the E-Port and E-Port Plus. The port next to the VGA port on the Plus is a DB9 serial port. But VGA would have looked worse anyway since it’s an analog signal. So again, to run two displays they need to both be running from DisplayPort.

@Joel28  In that case you're fine.  Note this sentence from the KB article you linked: "This only occurs on System with UMA Graphics without a discrete Graphics Option."  If you have an NVIDIA GPU, then you have a discrete graphics option in your system.  So yes, you should have full functionality of the dock.

In terms of a 240W adapter to buy, if it's a genuine Dell adapter that has a barrel style connector, then it will work with the dock.  Dell has kept the same 7.4mm barrel size for over 15 years now.  They do have a newer 4.5mm slim barrel for certain systems, but they don't make 240W adapters with that slim tip barrel as of this writing -- so any 240W AC adapter you find would work.  But again, note that I said genuine Dell.  I'm not familiar with the retailer you linked, so I can't comment as to whether they're selling genuine Dell products.  I will however say that counterfeit AC adapters are not a great idea to use, since they can damage the attached electronics (your dock and laptop) and even create a fire hazard.  If you want to buy straight from Dell, this link and this other link are appropriate 240W adapters.  The second one appears to have a longer power cord at 6 feet rather than 1 meter (approx. 3 feet).  If you are outside of the US, then search for the Dell Part Number of the desired adapter in the Dell online store for your local region.  The Dell Part Number of the first adapter is 450-AHHE, and the second one is 450-AGCX.

@jphughanThanks for your reply and help!

My Precision 7520 has also (in addition to the Intel (R) HD Graphics P630) an Nvidia Quadro M2200 GPU. So in this case you think all ports of an E-Port II Plus should work?

I found some good offers of used E-Port II Plus (PR02X) docking stations. But none of these offers has an 240W ac adapter included.

Which 240W ac adapter I should buy for an E-Port II Plus (PR02X). I found one (PA-9E) on the following link.

https://www.digitec.ch/de/s1/product/dell-pa-9e-240w-notebook-netzteil-439654

Do you think this ac adapter would work?

@jphughanGreat! Thank you for your time and help!

I will get in touch when everything has worked out.

Greets Joël

@jphughan I have now set up my workspace with an E-Port II Plus docking station, a 240W AC Adapter and the Precision 7520 Notebook. Everything works perfectly and it is fun to work.

Thanks again at this Point!

@Joel28  Thanks for following up, and great news!  Glad I was able to help.

The 7520 does not have a dual USB C port configuration and comes with only one optional USB C port. To use a newer docking station you would have to have both a power adapter and the docking station plugged into the laptop for this configuration. It's recommended to use either a E Port Replicator or an E Port Plus Replicator for the 7520.