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U2722DE + U2722D Daisy Chaining and KVM Switch Requirements
Hi Community,
Going through the official manual of the U2722DE as well as a few really informative posts on this forum on daisy chaining left me unfortunately with two questions:
The first is regarding the Daisy Chaining functionality:
My planned setup would consist of an U2722DE and an U2722D using Daisy Chaining. At the same time I would like to make use of the integrated KVM switch of the U2722DE by connecting a stationary PC and my laptop (Lenovo X1 2017) to it (basically the setup depicted on page 94 of the manual with the added daisy chaining to a second monitor).
- The PC would be using a display port connection to the U2722DE as well as a USB A to USB C cable using a USB 3 port of the PC.
- The Laptop would be using a USB C connection
My question is: Would I run into any limitations of if I hook both PC and laptop using only a USB A respective a USB C cable to two daisy chained monitors and make use of the KVM switch as well (mostly planning it to hook external storage solutions)?
The second question relates to the combination of the U2722DE and U2722D: Are there any differences in terms of their design other than the integrated KVM switch that would result in a visible difference between the two when used in a setup where they would be standing directly next to each other?
Thank you in advantage for any help with these questions.
jphughan
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September 24th, 2021 07:00
@scoove I forgot to mention one other item. Since you’ll be running a dual 1440p daisy chain from a laptop that only supports DisplayPort 1.2/HBR2 over USB-C, you’ll need to set the USB-C Prioritization setting on the U2722DE to High Resolution, not High Data Speed. That will cause the display to allocate all high speed data lanes in the USB-C connection to video, which you need in order to run dual 1440p via HBR2. The downside is that USB data speeds will be limited to USB 2.0, not 3.x. Running USB 3.x over USB-C requires two of its four high speed lanes, which cuts video bandwidth in half, and half of an HBR2 link isn’t enough for 1440p. Half of a newer HBR3 link would work, but your X1 from 2017 wouldn’t support that. If you only plan to have basic peripherals like a keyboard and mouse connected to the display, then that should be fine, but I’d avoid connecting something like a hard drive to it.
jphughan
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September 24th, 2021 07:00
@scoove If you connect the laptop using only a USB-C to USB-A cable, then you’ll only have a USB data path between the display and laptop to use USB peripherals plugged into the display. You would lose the video signal from the laptop to the display as well as the ability to charge your laptop from the display. I’m not sure why you’d be contemplating that setup. If you have a laptop that has a USB-C port that supports sending video and drawing power over USB-C, then use a USB-C to USB-C cable to connect it to the display. That essentially turns the display into a docking station for the laptop. That’s the entire purpose the U2722DE offers that functionality.
The U2722DE and U2722D won’t have any panel differences due to the different model designations, but it’s also true that not all examples even of a given model look identical. I remember ordering a pair of U2717D displays a while ago and one of the displays had a cabinet that creaked whenever I swiveled it. Dell sent out a replacement, but that one had a yellow tinge compared to the display I was keeping, even after I reset both displays to their factory defaults. So I ended up returning the replacement unit instead and asking for another. The second replacement had the same issue, so I gave up. Having a consistent panel look was more important to me than eliminating a creak when moving the display. But the point is that even if you ordered a pair of U2722DE displays, they may not look exactly the same.
scoove
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September 24th, 2021 08:00
Hi @jphughan
Thanks for the prompt and valuable information. As for your question - sorry there was a lot of setup related information in my post, seems I found it hard to structure all this information adequately:
No, I will of course use the USB C connection from my Lenovo Laptop to connect it to the monitor. However I also want to connect a second pc that has by now seen quite some years and hence only has USB A (USB 3.0) connections. For this stationary PC I was planning to connect it to the U2722DE using a Display Port cable and a USB A to USB C cable (the manual actually has a very similar example). However since video signals will run over the DP cable in this case, I would not expect any limitations.
Thanks especially for the second post that is extremely helpful. I will think about whether I am willing to live with that restriction or just go ahead and order two U2722D.
Do you happen to know if the U2722D does automatically detect the input signal or would I need to switch manually if my laptop is connected to lets say the HDMI input and the stationary PC to Display Port?
jphughan
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September 24th, 2021 08:00
@scoove Ok, the wording of your first question suggested that you were contemplating using the laptop using a C to A cable. But when using the USB-C to USB-A cable to the stationary PC, if you have any limitations they would come from the PC. The U2722DE supports USB 3.x Gen 2 (10 Gbps). It is technically possible to carry that over USB-A, but very few systems actually have USB-A ports that support that. Typically they only support USB 3.x Gen 1 (5 Gbps), in fact even many PCs with USB-C ports only support that speed. But I doubt that will make much of a practical difference. There are very few USB 3.x Gen 2 peripherals on the market in the first place, and likely won't ever be now that USB4 is here, and since you'll be running USB 2.0 to your laptop, you wouldn't want to connect high bandwidth devices to the display at all. So if you have a limitation at all, it will be a technical one, not a practical one.
I really wouldn't recommend dropping the U2722DE over USB 2.0. If you go with a U2722D, you'll be connecting and disconnecting three cables to your system (power, video, USB data) instead of one as you would be able to do with the U2722DE. Most peripherals you'd want to switch between PCs, such as keyboards, mice, printers, webcams, etc. would only use USB 2.0 in the first place.