Thanks for pointing that out. I was wondering why so many adapters/cables for sale only mention "USB" while also claiming to do 4K60Hz...
https://www.displayport.org/displayport-over-usb-c/ So Thunderbolt isn't required, only USB 3.1 Alternate Mode and a powerful (probably only *integrated*) GPU that can link to it. You might have hit some kind of bandwidth limitation using both USB-C ports at once. Although that doesn't make sense at Thunderbolt 3 speeds, it would make sense at USB speeds. And even if USB 3.1 speeds are being surpassed to support Alternate Mode your chipset/GPU might only know how to do it on one port at a time. So this might not be fixable... Also remember to try 'Ubuntu on Wayland' which uses a completely different code path for all this. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1886729 Title: Dell displayport YJ3Y6 adapter doesn't drive 4K screen properly To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1886729/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
