Dell’s dock didn’t work. The Belkin USB 3.0 hub did. For a while, at least. After a few months of fairly solid performance driving the 2x LG 34UC97 ultrawide monitors using 2x Plugable USB3.0 DP adapters, problems started to appear. One monitor wouldn’t come on. Or the other wouldn’t come on. Or they’d flicker wildly when actual work was being done. The bosses declared them “unusable” and worked from a meeting room, rather than stare at the pile of failing technology in front of them. Shame upon my family name!
It looks like the issue is the Belkin dock, rather than the Plugable adapters. While these docks are happily pushing twin 1080p monitors elsewhere in the business, it seems that pushing two lots of 3440×1440 monitors is too much for the chipset. I’ve kept them, and at some point I’ll test them out to see if they’re properly wrecked or whether they can enjoy an easy retirement pushing the same twin 1080p as their comrades.
So it was back to online shopping, trying to find something that would do the job. I have to say, the market for USB 3.x docks is moving at a serious pace now. It seems like none of the options I checked out in January were really available six months ago. In the end I settled for the Kensington SD4600P, a dock that advertises as supporting dual 4K, via one DP port and one HDMI port. They’ve been working for nearly two months now with fairly minimal issues; occasionally the XPS15 forgets which monitors go where, but that is quickly solved.
They seem fairly nice units, however there is one thing I will note. Of two installations on the same Dell XPS 15s, one was significantly easier than the other. The easy one was just checking that the video drivers were up to date, and we were away. The other struggled to drive both monitors at the same time until a firmware update was performed. And something in the firmware update had a terrible effect on the laptop’s onboard graphics. The lower half of the screen flickered and froze constantly after the firmware update (which should only have affected the dock!) and nothing I tried would fix it. Eventually the boss needed to go, so I shut it off. When it was turned on the next morning, it was fine. I have no idea what happened there. I had tried turning it off and on again, but it appears the extended power-down was the answer.