USB Docks Output to 4 Different 4K Monitors Over Single Connection

Just how many 4K monitors can your laptop connect to at once? Just one, and that's only if your GPU supports 4K output and you have a DisplayPort or HDMI-out port.

However, with a dock using DisplayLink's new DL-6950 chip, you can output to two Ultra HD monitors over a single USB connection. And if you daisy-chain two of those docks, you can output to four different 4K displays with that same single USB connection.

If you haven't heard of DisplayLink, you've probably seen its products in action. Every USB docking station, USB-powered monitor and USB to HDMI / VGA adapter is powered by one of DisplayLink's chips, which use your computer's own USB ports to output video to a monitor. 

At DisplayLink's Computex booth, the company showed off a unique configuration you probably wouldn't see in the wild -- one laptop connected to four 4K monitors thanks to a pair of daisy-chained docks, using the company's upcoming DL-6950 chip. The laptop was a current-generation Dell Latitude with a 6th Generation Core i7 CPU inside, and the two docks were reference designs for the 6950. 

MORE: Best Laptop Docking Stations

The Dell laptop was connected to the first dock by a single USB 3.0 cable and that dock was connected to two 4K monitors via DisplayPort cables. Dock No. 1 was also connected to dock No. 2 via a single USB cable. The second dock was then connected to two more 4K monitors via DisplayPort wires. The monitors were all mirroring the primary screen and smoothly playing a 4K video of some puppies. The Windows task manager showed only about 43 percent CPU usage.

You'll be able to buy one (or two) docks with DisplayLink's DL-6950 chip later this year.  Each dock is able to output to dual 4K monitors operating at 60Hz. In theory, a company could build a docking station with dual DL-6950 chips inside, which would give the same four monitor effect, coming from a single dock.

Multi-Monitor for Android

At its Computex suite, DisplayLink also showed how its technology can enable a multi-monitor mode for Android tablets and phones. The company already makes an app that lets users attach their Android devices to one of its docks and output to a single monitor. However, Android doesn't have multi-monitor support built in, so DisplayLink is trying to help manufacturers add such a mode to their devices.

I briefly tried out a Google Pixel-C tablet that was attached to two 1080p displays. When I tapped on an icon to launch an app on the tablets' screen, Android popped up a dialog box asking me which screen I wanted it on. After I tapped the Microsoft Word icon and selected the leftmost screen, that app appeared on the monitor as expected.

Unfortunately, because Android 5.1 doesn't have a windowed mode, any app you launch takes up an entire screen And you can't move apps from one screen to another. To close them, you need to use the tablet screen to bring up the tasks menu. 

DisplayLink said that it is working with manufacturing partners to add multi-monitor support to their versions of Android. However, those implementations may not look exactly like what we saw.

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Avram Piltch
Online Editorial Director
The official Geeks Geek, as his weekly column is titled, Avram Piltch has guided the editorial and production of since 2007. With his technical knowledge and passion for testing, Avram programmed several of LAPTOP's real-world benchmarks, including the LAPTOP Battery Test. He holds a master's degree in English from NYU.