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UHD/4K resolution in AmigaOS4

Posted: Fri Dec 31, 2021 9:17 pm
by Raziel
I wonder if anyone is (was ever) able to use 3940x2160 under AmigaOS4 (given a capable gfx card and monitor).

I have a RadeonHD 7950 and LG UHD monitor.
I can get 2560x1440 just fine, but not UHD.

Any hints?

The monitor says it supports 3940x2160@30Hz, but that can't be true, since the vsync refresh rates are 56-61Hz...
Windows10 through DisplayPort works fine

Thank you

Re: UHD/4K resolution in AmigaOS4

Posted: Mon Jan 03, 2022 10:30 am
by Raziel
Anyone?

Just wanna know if it's a driver or hardware issue

Thanks

Re: UHD/4K resolution in AmigaOS4

Posted: Tue Jan 04, 2022 7:52 pm
by MichaelMerkel
i have an Eizo Felxscan EV3895 here.
it offers a resolution of 3840x1600x60
i can not connect it to the amiga with that resolution in 60hz. it only works with 30hz. using a "Radeon R9 270X Devil"
it is connected via HDMI.
i *guess* that the HDMO port of that graphicscard only supports up to 30 hz in that resolution.

for example, on our windows pc machins we have the same monitor connected vie display port. wokring fine in that resolution. it is an onboard graphicchip. if i connect it via HDMI (same monitor and mainboard - just other port) it also only shows with 30hz.
so my conclusion: HDMI is the problem here.

have you checked the exact specs of your card? should it output that resolution/frequency on the hdmi port?
and you'r using a very good hdmi cable? afaik you need at least a HDMI 2.0, better a 2.1 cable.

i'm currently using only a resolution of 2560x1600 which works fine with 60hz.

it really is time for the graphics driver to support display port and also audio overe display port (or hdmi).

regards...
michael

Re: UHD/4K resolution in AmigaOS4

Posted: Tue Jan 04, 2022 8:46 pm
by Raziel
See here for debug output, i'd love to see yours from serial if possible.

I have 5 different HDMI cables, all of them claim to be UHD capable, but i have no means to test them yet (have to check if PS4 can do UHD).

The internet says yes to UHD resolutions with that card
See here: https://www.gpuzoo.com/GPU-AMD/Radeon_HD_7950.html
Video features
Multi-monitor: Up to 4 displays
Maximum DP resolution: 4096 x 2160
Maximum DVI resolution: 2560 x 1600
Maximum HDMI resolution: 4096 x 3112
The frequency shouldn't matter as the monitor features four HDMI slots, two which support UHD at 30Hz, two with 60Hz (but it seems graphics library can't cope with that)

HDMI revision on the card is 1.4a, while the monitor supports up to 2.1, i think (backwards compatible)

Like it's lined out in the thread i linked to, it seems to be some kind of bug in graphics library

Re: UHD/4K resolution in AmigaOS4

Posted: Wed Jan 05, 2022 8:27 pm
by MichaelMerkel
Raziel wrote: Tue Jan 04, 2022 8:46 pm See here for debug output, i'd love to see yours from serial if possible.
i'm using DCC and have not defined any manual resolutions.
shall i see a debug output, too?
i tried some manual ones some weeks ago but i saw no effect after reboot. so i disdabled it again.

regards...
michael

Re: UHD/4K resolution in AmigaOS4

Posted: Wed Jan 05, 2022 8:40 pm
by Raziel
i'm using DCC and have not defined any manual resolutions.
shall i see a debug output, too?
Probably not, since DDC just takes the supported resolutions from the gfx cards EDID (iiuc) and uses the highest possible resolution by default (that's how it works on the pc), but contrary to the amiga the pc uses the full potential of the gfx card/monitor combination.

Only if you add manual resolution/frequency pairs (that are not supported) will get you (error) debug output.

Regarding manual resolutions, yes, same here, that's the underlying problem.
Even if I want to use a manual resolution, I can't, because graphics library is too strict (or so i understand it)

I don't think a supported DisplayPort would help, since the problem lies with graphics library.

:-(
Too bad, got a new monitor and can't use it's full potential.

I would love to test a beta version without those limitation, but would understand if that's not possible, being no betatester.
Could someone please add this to the bugtracker at least?

Re: UHD/4K resolution in AmigaOS4

Posted: Wed Jan 05, 2022 9:43 pm
by MichaelMerkel
i try to address this in the beta mailing list/bugzilla.
AFAIK there already is one bugreport regarding UHD.

regards...
michael

Re: UHD/4K resolution in AmigaOS4

Posted: Wed Jan 05, 2022 11:21 pm
by Raziel
Thank you

Re: UHD/4K resolution in AmigaOS4

Posted: Mon May 02, 2022 4:19 pm
by trgswe
HDMI 1.4 only supports 30Hz, for 60 Hz you need HDMI 2.0+, HDMI 2.1 for 8k at 60Hz, on the amiga this probably means one of the latest cards rx580 has hdmi 2.0, r9 290x has hdmi 1.4a, generally you need DP 1.2 to get UHD with 60Hz.

Re: UHD/4K resolution in AmigaOS4

Posted: Mon May 02, 2022 6:43 pm
by Raziel
@trgswe

That shouldn't be a problem. I already own a RX5xx card.
Sadly, the chances seem to be higher to get an updated UBoot for the X1000 which support those cards, than an update to whatever will support the UHD resolutions in AmigaOS4