Hmm, it seems Thunderbolt-DisplayPort cables are pretty rare. Instead of searching for those I suggest looking for adapters that are explicitly for "Thunderbolt" and not "USB".
USB 3.0 has a bandwidth of 5 Gbps USB 3.1 has a bandwidth of 10 Gbps 4K at 60Hz however requires 3840x2160x4 (33177600) bytes per frame, 265420800 bits per frame, or ~16 Gbps. USB never had a chance and at best would give you only 30Hz. So make sure your adapters are "Thunderbolt" and not "USB". Thunderbolt 3 in your laptop supports 40 Gbps which is enough for 4K at 120Hz. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to 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 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
