I am convinced this is a bug.
I had to return 3 different notebooks, for different reasons,
And all of them only displayed 4k@30Hz in HDMI connected monitors.
Nvidia proprietary, Noveau and AMD.
On Windows the monitor HDMI 4k@60Hz is ok, as well as
with thunderbolt to HDMI also 4k@60Hz
Connected to DisplayPort cable, I get 4k@60Hz running Linux.
So there is definitely a bug in HDMI.
.
Your description smells rather like https://bugzilla.opensuse.org/show_bug.cgi?id=1177384 and a DVI thread here a few days ago. I sense something has been going on with CRTC programming that isn’t getting adequate testing before getting mainlined. You may wish to report a bug that mirrors 1177384, as it may get quick attention if reported anything like 1177384. ISTR similar trouble with certain display and connector combinations within the past several months, DVI working as expected, but HDMI and/or DP not.
I bought a 4k once, but quickly returned it, and haven’t found a suitable deal since, so sticking with 2k and 1920x1200 for now, and preferring DisplayPorts anyway. I like having latching connectors, as I do a lot of switching, and don’t always manage on first try to tell when an HDMI connector is in all the way.
Does it help to use an older than latest kernel? Which openSUSE are you running? Why not use DisplayPort? Are you using a TV rather than a computer monitor?
I am searching for solutions. this is appareantly not a OpenSUSE only issue.
I just installed Kubuntu 20.10 beta, because OS15.2 won’t even start.
But with all of the three notebooks, non would display 4k@60Hz neither OpenSUSE nor Ubuntu.
The web is filled with these reports.
https://www.google.com/search?channel=fs&client=ubuntu&q=fedora+4k%4060hz
https://www.reddit.com/r/linux/comments/7w4tnv/how_i_got_my_4k_monitor_working_at_60hz_in_linux/
https://forums.developer.nvidia.com/t/4k-60hz-works-in-windows-not-in-linux-workaround-found/43142
As the DP works at the same monitor. thunderbolt to HDMI and HDMI work running Windows 4k@60Hz, I would call this an linux HDMI bug.
And this with serveral monitors, AMD and NVDIA, open and proprietary drivers.
Probably those forum posts fall on few if any developer ears. In order to make the problem visible to developers I’d file a report on https://gitlab.freedesktop.org/xorg/xserver/-/issues/new?issue[assignee_id]=&issue[milestone_id]=. If no direct traction results I’d expect at least a pointer to a better place. If you’re really ambitious, try filing on each of the primary DDX drivers:
https://gitlab.freedesktop.org/xorg/driver:
https://gitlab.freedesktop.org/xorg/driver/xf86-video-amdgpu
https://gitlab.freedesktop.org/xorg/driver/xf86-video-ati
https://gitlab.freedesktop.org/xorg/driver/xf86-video-intel
*] https://gitlab.freedesktop.org/xorg/driver/xf86-video-nouveau
FWIW, if this happens when you connect and external 4K monitor, the hdmi cable is version 2.0b (IINM) or higher? Version 1.4 only support 30 Hz.
I have two 4K monitors connected to a GTX 1650, one display port and the other hdmi, and both run at 60 Hz. LEAP 15.1 with G05 proprietary drivers.
RTFMRTFMRTFMRTFMRTFMRTFMRTFMRTFMRTFMRTFMRTFM RTFM HDMI ports only supports 30Hz while DP 60Hz. stupid me:quiet:
Then how is it that Windows, as reported in #1, can do HDMI 4k@60Hz???
because me stupid. looked at the notebook panel resolution. just changed from the XMG that had 144Hz and had that in mind. Just saw the 60Hz
WRONG! You just need HDMI 2.0b or higher for that (GPU and cable). See my post above.
HDMI 2.0 or HDMI 2.0a also supports 4K video at 60 Hz: HDMI - Wikipedia
HDMI 2.0 increases the maximum bandwidth to 18.0 Gbit/s.[112]](HDMI - Wikipedia)[113]](HDMI - Wikipedia)[114]](HDMI - Wikipedia) HDMI 2.0 uses TMDS encoding for video transmission like previous versions, giving it a maximum video bandwidth of 14.4 Gbit/s. This enables HDMI 2.0 to carry 4K video at 60 Hz with 24 bit/px color depth.
Right, my bad.