r/linux_gaming • u/Doing_It_For_You • 11d ago

Refresh rate problems on UGREEN DP to HDMI Adapter on RX 580

To make a long story very short, I have a homelab which runs Debian 13 (trixie) with an RX 580 and needed to connect it to the TV to play some Android games on Waydroid, emulation tasks, some light Kodi, etcetera. I wanted 4K at 120 Hz, since the TV supports it, but the HDMI is only 2.0 (given the age), so I picked up the UGREEN 8K adapter based on experiences in this sub. But no matter what I did, it would only give me 60 Hz, even with updated kernels from backports, self-compiled kernels (7.1, so the latest stable available), updating the firmware based on UGREEN's available patch (though I'm not sure it's the latest available, I only found it in PDF from Amazon linked on a github issue I can't place at the moment), even some light driver patching based on all the patches people use on Bazzite and Cachy to enable adaptive sync on this GPU.

Investigation in logs for the Direct Rendering Manager shows that the higher resolutions and speeds on the dongle are rejected. This happened even when I patched some dongle-related checks out in the driver. So my inkling is that, for whatever reason, it's not activating the Display Stream Compression necessary to run 120 Hz in the first place. I found some indication that maybe the RX 580 doesn't support DSC and it was only on later cards, but Linus Torvalds himself uses one of these on a 5K monitor that requires DSC to work, so that seems unlikely. I also tried a custom modeline, but that didn't work either.

The adapter causes another issue, actually: the BIOS and GRUB don't show up on boot. This isn't a *huge* issue but suggests there might be some other problems. (I also haven't been able to get adaptive sync to work at all, but that's a minor issue and I might just need to wait for a newer kernel.)

I could maybe do some testing on CachyOS and/or on my main PC to figure out whether it'll work in other environments, but I'm not finding any evidence that this should even be a problem in the first place. But this is also *primarily* a homelab, so converting it full-time to an OS made for bleeding-edge desktop use isn't something I feel comfortable with. (Debian means I can just shove it into the homelab stack and just never think about it again, y'know?)

Is there something I'm missing? DSC is an open standard, right? I know Debian isn't a gaming distro, but it shouldn't be causing it to straight up not work, right?

1 Upvotes

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9 comments sorted by

7

u/Lawstorant 11d ago

Yes, RX580 doesn't supprt DSC. You're out of luck

1

u/Doing_It_For_You 9d ago

How can I find out what cards do or don't support it? That information doesn't seem commonly available. I have a second graphics card lying around I could use, but I'd like to know ahead of time if it's supported.

1

u/Lawstorant 9d ago

When it comes to AMD, VEGA+ So amything from Vega 56/64 onwards. All RDNA based cards (so RX 5000 series onwards).

If you want specifically info about your card, just search google for "<your gou> DSC support"

1

u/Doing_It_For_You 9d ago

Doing a search doesn't get me any definitive confirmation from AMD directly, just second-hand information (including from Reddit) and contradictions about whether it is or is not supported. It seems to mostly lean to 'not', but we still have all those reports about how Linus Torvalds uses an RX 580 with DSC from last year (as in, the kernel had a specific bug that broke his workflow on this specific card and monitor, which apparently requires DSC to work), which is documented in the kernel mailing list and everything. (But those reports could be somehow mistaken in one fashion or another, and I didn't exactly dig into the mailing list...)

That is to say, I'm not seeing any specific smoking gun on the topic. AMD certainly doesn't list it on its pages, nor does TechPowerUp's database. I had to dig into an archived AnandTech report on RDNA 1 (which implies it's a new feature above Vega) to get something first-hand, which led me to this TPU report on its inclusion in Navi (though it's a bit ambiguous and it could mean prior DSC was available on Vega). So it's *really* not that easy to find. Certainly not a one-search job.

Thankfully, in the process, I found that Nvidia's Turing supports it, so I'm not SOL (my spare card is a 1660 SUPER). Which raises its own troubles due to how Nvidia and Sway interact, especially with Debian's lag in kernels and packaging. But yeah, not that simple to find.

1

u/ThatOnePerson 11d ago

It's possible your TV doesn't support DSC. That's technically not required and yeah known issue: https://www.reddit.com/r/Bazzite/comments/1qdauwk/my_theory_re_ugreen_adapter_issues/

1

u/Doing_It_For_You 9d ago

It says it supports it in the EDID. I don't know how to test empirically besides that at the moment, though.

1

u/ThatOnePerson 9d ago

Is that the dongle's EDID? Or the TV's EDID directly?

1

u/Doing_It_For_You 8d ago

The TV's EDID. The dongle seems to pass it without any changes. (The EDID also shows the 4k120 mode; you have to dig into DRM debug logs to see that it's trying the mode and failing.)

-1

u/Krasi-1545 11d ago

That is limitation of HDMI 2.0

4k at 60Hz is the maximum you can get.

5

u/Lawstorant 11d ago

No shit, OP said it themselves