Dual Monitors

Thanks jphughan......

From reading your posts, seems to me I would be better off to go ahead and return the D6000 and purchase the WD19.  The D6000 came from Amazon with free returns, so the only cost to me is the higher $19 more for the WD19.  You agree.

@FD282  you may have read one of my posts about that.  Fyi since the WD15 was introduced, the WD19 has replaced it, and it has dual DisplayPort outputs if that makes it easier for you, although the U2417H has DisplayPort, Mini-DisplayPort, and HDMI inputs, so you've got multiple options for connecting these displays, even if you only had Mini-DisplayPort and HDMI outputs on the dock.

In any case, to answer your larger question, the D6000's limitation is a bit more nuanced.  The issue is that since the D6000 uses DisplayLink technology rather than tapping into a native GPU output, a Windows limitation means that only the system's primary GPU will be used for content being displayed on a DisplayLink display -- which in the case of Intel+NVIDIA GPU systems will be the Intel GPU.  When you use a dock that taps into native GPU outputs, like the WD15 or WD19, then on most systems, the native GPU output feeding the USB-C port is still coming from the Intel GPU, but the key difference here is that you can still take advantage of NVIDIA Optimus technology.  That's a technique whereby when the NVIDIA GPU's additional horsepower is required, it can step in as a "render-only" device that passes completed video frames to the Intel GPU for output to the displays.  Many Intel+NVIDIA GPU systems on the market today have most or all display outputs physically wired to the Intel GPU and tap into the NVIDIA GPU exclusively through this mechanism.  There are some systems that have the NVIDIA GPU directly wired to some outputs, but they're relatively rare.  The main reason for the Optimus design is battery life, because that design means that when the NVIDIA GPU's performance isn't required, it can be completely disabled.  By comparison, if the NVIDIA GPU was directly wired to display outputs, then it would need to remain active whenever a display was attached to that output, even if nothing graphics-intensive is going on -- and some people use external displays/projectors while running on battery power.

So why does this matter?  Optimus means that content being shown on displays attached to the USB-C port, either directly or through a docking station that relies on the USB-C port's native GPU output, can be accelerated by the NVIDIA GPU.  However, Optimus does impose some limitations, because there are certain technologies that the Intel GPU doesn't support passing through and/or that the NVIDIA GPU can only use when it has direct control of the display output.  These technologies include G-Sync, Adaptive V-Sync, stereoscopic 3D, and VR, possibly among others.  These limitations are incidentally why a relatively small handful of laptops have the NVIDIA GPU directly wired to at least some display outputs, so that those laptops can use those technologies.  But due to the somewhat niche use case of those technologies, the laptops set up this way are typically hardcore gaming or professional workstation laptops.  But again, the vast majority of laptops just use Optimus despite these limitations.

So if you don't care about using any of those technologies I just mentioned, then you'll be fine.

@FD282the only reason to keep the D6000 would be if you think you might want to run dual displays with higher resolutions than 1920x1200 each with that system, because that's all you can run with the WD19.  With the D6000, you can run three displays up to 4K each, thanks to the double-edged sword of its compression technology.  The only way to run higher-end display setups while still using the native GPU output capability would be to dedicate the entire USB-C port to video rather than a docking setup, in which case you could run dual displays up to 2560x1600 each.  This setup would be implemented using a USB-C DisplayPort MST hub or a DisplayPort daisy-chain setup with no dock involved -- but then of course you lose the other benefits of the dock.  The only remaining option would be Thunderbolt 3, which allows high-end display setups AND a docking station, but that system seems not to support it.

But if you're fine with dual displays up to 1920x1200, then yes I would definitely get the WD19 for the extra cash.

Hi there,

I have purchased, a Dell P2720DC monitor & a Dell P2720D monitor. They have been daisy chained, and I wanted to know if the Vostro 5590 will be able to support dual monitors and charge via USB-C, connected to the P2720DC monitor.

Thanking you in advance

@PICKJONO  A Vostro 5590 will NOT be able to run those two displays both at their native resolution and refresh rate when they are set up as a daisy chain using USB-C.  This is due to a combination two facts, namely that the Vostro 5590 only supports DisplayPort 1.2/HBR2 over USB-C rather than DP 1.4/HBR3, and also that the P2720DC does not offer an option to have it configure the USB-C link to run only USB 2.0 instead of 3.0 in order to allow more bandwidth for video, which WOULD have allowed a dual QHD 60 Hz daisy chain setup.  The U2719DC does offer the option I just described, which Dell calls "USB-C Prioritization".  If you had that as your first display in the chain and set that option to High Resolution, you could run a dual QHD 60 Hz daisy chain as long as you were ok only having USB 2.0 data speeds to the USB ports built into the U2719DC.  But the P2720DC always sets up the USB-C link to carry USB 3.x data, which cuts video bandwidth in half, and on a DisplayPort 1.2/HBR2 system, a half bandwidth link isn't enough for dual QHD 60 Hz.  It would be for a DisplayPort 1.4/HBR3 system, but your system doesn't support that.

If you'd rather not replace the P2720DC with a U2719DC and you would also be ok having only video and power running over USB-C, i.e. with no USB data at all, then you do have a workaround.  This adapter will allow you to use the USB-C port for video output at maximum bandwidth (since it's not running USB data) and also includes a USB-C port for power passthrough.  So if you got this adapter, you'd connect the USB-C cable from the display to this adapter to supply power, and then connect a DP cable from the adapter to the display for video.  And then your daisy chain will work at 2x QHD 60 Hz.

@jphughan , thanks for the detailed response. I haven't purchased the Vostro 5590, could you suggest a Dell Laptop that would support my requirements.

If I were to drop the display resolution, would this work?

@PICKJONO  Happy to help.  To answer your follow-up questions, yes if you were to lower your resolution to 1080p on each display, then any laptop with a USB-C port that supports video output would be able to run that daisy chain setup.  But I really don't recommend running QHD displays at 1080p resolution.  In addition to losing a bunch of desktop real estate, running any display below its native resolution never looks great.  So I wouldn't go there.

In terms of other laptop options, if you're NOT willing to get a docking station, your options for running dual QHD displays as a daisy chain from a USB-C port when USB 3.x data is active (which it always is with the P2720DC) would be limited to laptops that have either a) a discrete GPU that has direct control of the USB-C output (these are fairly rare especially among Dell systems) or b) an Intel CPU that uses the Ice Lake or Tiger Lake architecture, since those include a newer Intel GPU generation.  Ice Lake CPUs are Core 10th Gen CPUs with models that end with a "G" followed by a number -- NOT Core 10th Gen CPUs ending with a "U" or "H".  And Tiger Lake CPUs are Core 11th Gen CPUs with that same "G" followed by a number.  The main laptops in Dell's line that use those CPUs are the recent XPS 13 models.  But since you initially asked about a Vostro 5590, I'm guessing you want a 15" system.  I don't know of any 15" systems with those CPUs.  The 15" systems in Dell's lineup seem to use the U and H Series CPUs.

If you ARE willing to get a docking station, then your options open up considerably.  All you'd need is a Thunderbolt 3 dock like the WD19TB, and then any Dell laptop that has a Thunderbolt 3 port will run dual QHD plus USB 3.x.  But of course Thunderbolt docks aren't cheap, and I'm guessing that you wanted a USB-C display specifically to avoid having to get a docking station.

The final option would be to connect each display to the system separately.  Any laptop with a USB-C port that supports video output can run just the P2720DC at its native resolution and refresh rate AND run USB 3.x -- plus drawing power from the P2720DC as long as the laptop itself supports being charged via USB-C.  Not all Dell laptops with USB-C ports do, however.  And then you can connect the P2720D display separately, using an HDMI output if the system you purchase has one, or else a USB-C to DisplayPort cable if you get a system that has multiple USB-C ports that support video output.  Of course this means you have to connect two cables, but it dramatically expands your options for laptop models without requiring you to get a docking station.

Hopefully this helps!

@jphughan , Thank you again, you have been extremely helpful. USB-C is more complex then meets the eye. Based on your suggestion, would the VOSTRO 5501 support my requirements?

@PICKJONO  Interesting find. Yes, it appears that it would work, since it has the right type of CPU and a USB-C port that supports video output and Power Delivery.  Evidently I hadn't looked at Dell's lineup of 15" laptops recently enough.  (Fair warning: I can't confirm from my own personal experience that the 5501 will behave the way you want it to.  The specs suggest that it will, and if I had your requirements, I would consider purchasing that system myself.  But it's also true that not everything that SHOULD work in the tech world always DOES work.  Good luck!)