Have you tried Android?
Rock 5B - HDMI 4K 120 hz
Yes, Android is limited to 4K60
I have no further suggestions. It might be that Rockchip has not released a kernel with this enabled.
One long shot though - maybe you can try a mainline kernel (armbian + Linux 6.11) but it most likely will be even worse.
RK3588’s spec shows it doesn’t support 4K@120hz, https://www.cnx-software.com/pdf/Rockchip RK3588 Datasheet V0.1-20210727.pdf
thanks! There is no word about 1440p 120 hz either, but that works… If it is capable of 8k60, shouldn’t 4k120 be possible? I thought HDMI 2.1 supports 4k120.
The above hardware specs says its limited to 60hz output for everything so its probably a lower level limitation of the video processor than the HDMI specification.
HDMI 2.1 doesn’t mean the system supports all of the features of that either, it did initially but the HDMI Forum then changed it so now you can have HDMI 2.0 level spec ports claiming to be HDMI 2.1.
Thanks! Do you have any recommendations for a SBC that supports 4k120 and h265 decoding?
Probably Rock6, when it comes out 
When will that be?
Aren’t Orange PI 5 and Rock 5B pretty much the same? Looks like 4k120 is possible on Orange Pi 5…
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This just decodes 4k120hz video streams to reduce game streaming latency, not hdmi display 120hz
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It is not. I was able to do 4k120 with mo123 image. People here just reply without even reading the specsheet. It can absolutely output 4k120.
Get it from here [ROM] Rock5A/B AndroidTV 12 by mo123 - ROCK 5 Series - Radxa Community
You need to PM mo123 to get the password. I get 4k120 at 4:0:0 but depending on your setup you can do better. I haven’t tried HDR, I’m assuming it’s a no go.
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For the 5b the 4k120 port is the one second one counting from the usbc port. So I’m thinking that maybe I wasn’t testing both ports coming from a pi and was stuck to 4k60 because I kept connecting to the non-8k HDMI port? I don’t really know, but it’s worth noting.
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@Fortean I could set Android to 4k120 4:2:0.
However, moonlight was not “fluid”. Have you tried moonlight with hevc/h265 and 4k120? What bitrate? How high was the decoding latency?
4070 on a gigabit network, I think maximum bitrate.
Av1 is… strange. Sometimes I get 10ms some others 100ms. I also have the 5b for moonlight, I got it working on the ubuntu image (compiling it myself) but no 4k120. I will try again on hdmi1 on a while.
Looks like you are limited by your host/4070. Have you tried setting NVENC to P1 in Sunshine? AFAIK 4070 has only one hardware encoder, not sure if this is enough for 4k120 (with higher NVENC presets).
Please let me know how your Ubuntu test goes.
@woiza P1 on and nightlies sunshine with somr fixes that are relevantto me. Yeah I’m limited on this particular game (god of war on max) but i generally play jrpgs that do fine at 4k120). I’ll install it sometime this week but I had seen that opi5 thread and I think it’ll be comparable. Maybe, since I’ll be compiling from source with the proper libraries from joshua riek it’ll do well on av1 which would be perfect. What’s your setup, and did you manage to see what the issue was with moonlight nor working properly?
I have a 3090, a Rock 5B, and a Xbox Series S.
I think my Rock 5B is broken. I have packet loss and difficulties to download large files and clone repos using Radxa’s latest Debian image. With Mo’s Android image I get all sorts of glitches, packet loss, and lag.
I will try Joshua Riek’s image next, hopefully this will work and my Rock 5B is not broken. If not, I will continue using Moonlight on Xbox (4k120, 150Mbit/s, 4:2:0, 0 lag/latency…)
@Fortean I was finally able to use Radxa’s latest image:
My Rock 5b now outputs 4k120 4:2:0 to my LG C1 tv. I built moonlight-qt with [https://github.com/nyanmisaka/ffmpeg-rockchip/wiki/Compilation)
Bitrate is set to 120 MBit/s.
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