Thread 106195121

So is this why my LG C2 looks off on Arch w/ an AMD card (stuck on 4:2:0 chroma when at 4K/120hz)? Anyone with a similar setup manage to get around this horseshit?

I know this article is over a year old but I guess they're still sticking to their retarded decision a year later, I don't want to have to move back to Windows or buy a new monitor just because these cunts have their heads up their own asses

>>106195121 (OP)
nope, I was going to upgrade my HTPC to a newer AMD APU system and after all the reading I did I gave up on the idea and just bought a Onn 4K Pro box to handle my media. AMD can't do 4k144 on any of those cards on linux natively and there aren't even adapters that can handle it because they need to be active not passive DP 2,0 to HDMI 2.1

>>106195461
I see people recommend the CableMatters DP1.4 -> HDMI 2.1 adapter saying it works for 4K120 4:4:4, I have one on the way but I'm skeptical because as you said the bandwidth shouldn't be enough for that.
I just found this other one that should work in theory but nobody ever mentions it. guess I'll just order a bunch of different ones and return what doesn't work (maybe all of them)

pro tip: only works if viewed at 1:1 scale

>>106195705
yeah that looks messed up for me. i was using pic rel to check, but it first became obvious when i saw red text on a black background in my terminal and it looked fucked up. also noticed it on here, the little red thread watcher icon in the top right on 4chanX looks illegibly blurry on 4:2:2 or 4:2:0

>>106195672
DP 1.4 doesn't have enough bandwidth to drive 4k120+ let alone 4k120+ with 4:4:4 hence the issue. You either suffer with banding or DSC garbage.

>>106195672
I have the Cable Matters 102101 adapter and it does 4K120 4:4:4 with my LG C2 hooked up with a 10 meter "RUIPRO" "8K" optical fiber HDMI cable
it even does VRR
but my GPU is Arc A750, no AMD here

>>106195672
>I have one on the way but I'm skeptical because as you said the bandwidth shouldn't be enough for that.
>>106195808
4K @ 120 Hz, 8-bit 4:4:4 = ~23 Gbps
4K @ 120 Hz, 10-bit 4:4:4 = ~30 Gbps
dp 1.4 can do 25.9 Gbps.
dp 1.4 also support DSC 1.2 which is lossless, I've read on wikipedia that the compress ratio can go up to 3.75:1 for 8bit and 2:1 for 10bit so a 4k120Hz10bit is doable without loss.

4k120Hz10bit with a compression ratio of 2 == ~15Gbps without losses so it's fine

>>106195843
read https://gitlab.freedesktop.org/drm/amd/-/issues/1417 , also, DSC is not lossless. also, I'm talking HDR10+ I know for a fact DP 1.4 can't drive my TVs 4k 144hz @ HDR10+/DV which iirc is 12bit

>>106195843
this is one of the more sane people in that thread that after years has realized its futile and given up.

>>106195822
i'd imagine it must be using DSC, but if it's unnoticeable then whatever I'll take it over fucked up text.
i'd bet even in the worst cases DSC is less noticeable than 422/420

>>106195928
i had to use windows yesterday for BF6 and couldn't wait to reboot back to linux, i'd honestly rather buy a DP2.1 capable OLED monitor than switch

>>106195891
>DSC is not lossless
"visually" lossless as they say, I don't have any experience with how it looks, if you don't want DSC at all then yeah it won't work.
>I'm talking HDR10+
this is 10bit + dynamic metadata
>DV
12bit + dynamic metadata
I suppose dynamic HDR makes DSC even worse?
>>106195928
yeah it's shame, I hate the hdmi mafia so much, dp needs to take off in tv space

>>106195121 (OP)
some guy on reddit got around it by using a dp to hdmi dongle

>>106195931
If I recall Intel solved it by wiring HDMI through Displayport 2.0 (as an emulation layer), and nVidia did it by just shipping the encrypted binary blob with their proprietary driver. I assume the open one does similarly. It's only AMD that hasn't provided a working solution to their users, requiring people to spend hundreds on adapters and firmware flashing just to try and get it half working. Once I realized that even if I bought the latest AM5 APUs none of the boards themselves ship DP 2.0 even though the CPU is rated for DP 2.1.

On CachyOS, an LG c1, and a 9070 xt, I have 4k / 120 / VRR / HDR / 10b color working over this adapter with this custom firmware. Sometimes it fails on a cold boot. Unplug/replug fixes it. What you are trying to accomplish is possible; good luck.
https://a.co/d/dtIHjBt
https://www.dropbox.com/scl/fi/re1oa2zg9v7yd0ttgb7ew/Custom-firmware-for-102103.zip?rlkey=0d1aohrdcr3ajof41kvx7u81j&e=1&st=q5nesci4&dl=0

>>106195931
>but if it's unnoticeable then whatever I'll take it over fucked up text
yeah, it's decent. I'm not even 100% sure whether I'm running DSC or not with this setup, but when the HDMI link drops to 4:2:0 (on one of my monitors, which is connected directly to the HDMI output of the GPU; i.e. it's not the C2 where I experience this) I can immediately tell, especially when working with text.

Works on my c2.
Have you tried unplugging it and plugging it back in?

>>106196105
>rtx4090
this is why it works

>>106196055
>flashing utility requires Windows
kek
anyway, that's pretty neat. The adapter works fine for me with stock FW, but I wonder how this custom FW was made. Funny how manufacturers always find ways to fuck up otherwise-decent hardware and the community has to deploy fixes like this. Had this experience with a Logitech mouse and Creative heapdhones. Capable hardware crippled by trash firmware.

>>106196135
Yeah, ran into that issue too. I'm retarded, so I:
Installed windows 11 to a small partition of my laptop.
Downloaded Rufus, and used it to make a windows2go win11 installation on a external SSD I had laying around.
Wiped the windows 11 partition.
Used newly created windows2go SSD to boot my main PC. Used that SSD to download and run the firmware update tool. Can't believe it all worked, but it did.

>>106196187
why not just use hiren bootcd to get access to WinPE?

>>106196236
I couldn't get my winPE to recognize the adapter. Probably my fuck up, but now that I have the win11 windows2go, I think I prefer it anyway.

>>106196055
thanks, my setup is exactly the same just with a C2 instead of a C1, so hopefully a good sign I can get everything working when this adapter delivers tomorrow

>>106196105
it's specifically an AMD+Linux problem because HeebDMI blocked AMD from adding HDMI 2.1 support to their Linux driver, it works fine if I boot into Windows but then I have to use Windows which is just trading one downside for another

>>106196292
as the custom fw is for 102103, make sure to check the engraving on your adapter

>>106196338
I flashed it on my 102101. Like I said, surprised it worked, but other than sometimes falling back to 60hz/12b on a cold boot, it's been solid. Haven't even seen it flicker.

>>106195121 (OP)
HDMI is shit fuck all that license and content protection shit, use DisplayPort.

>>106196453
>just use a thing that no modern TV includes
funny guy, there are no Displayport TVs anywhere, apparently some upcoming models will have a Type-C Displayport on them but yeah...

>>106196453
honestly if I can't get this working with the adapter route I'll probably spring for one of those newer OLED monitors that support DP 2.0+ and move my C2 to the bedroom.
sucks that I even have to consider this as the only thing wrong with my C2 after 4 years is one barely noticeable dead pixel at the very top of the screen (still no burn-in somehow), I am definitely on team fuck HDMI now because of this shit

>>106196720
oled monitors are very small <42" so that will look weird in the living room when 55" and bigger tv are getting mainstream
>I am definitely on team fuck HDMI now because of this shit
fuck the hdmi mafia
fuck the broadcom mafia
fuck the mpeg mafia
fuck the usb mafia
fuck the qualcomm mafia

we can't have nice things because of these patent trolls, fuck them

>>106196932
im using a C2 as a desk monitor, if anything I should probably go smaller anyway

>>106196187
Or or you could use pendrive or sd card for that.

>>106196720
It's all going to be okay, anon. Remember, after you flash, you've gotta unplug/replug for it to take effect. I love you.

>>106195121 (OP)
>buy a new monitor
Worst-case scenario you buy a DP to HDMI adapter, not a new monitor.

maybe someone will release an un-official patch for the driver to make it work illegally.

>>106195121 (OP)
just use Displayport?

>>106196105
You special

Don’t use a TV for gaming.

>>106198207
it doesn't work on amd because they keep their blob in open source rather then proprietary. thats the whole point behind the hdmi forum shit. it works on nvidia because their firmware blob is proprietary.

>>106200529
in theory couldn't AMD package just the HDMI driver as a closed source blob?

>>106196292
got the adapter, no VRR yet but it looks like I got 444 at 4K/120 so I'm happy until I can be bothered to boot into windows and set up the firmware, can vouch for that cablematters adapter working as a workaround

>>106195121 (OP)
I'm glad my 55" NEC commercial panel just has DP inputs.

>>106195979
I blame the hebephiles that are gatekeeping it and requiring solutions from amd, nvidia, intel and whoever else will come to market.
Workarounds shouldn't need to exist at all.

Imagine the wasted energy that goes into engineering workarounds. Now imagine the energy, capital, man hours that go into asking approval from the HDMI forum? That's not just wasted human potential but it's waste that's harmful to the planet beyond a 13 year old throwing a disposable vape away on a beach. Because at least the 13 year old got something out of it.

>>106195121 (OP)
freetards everyone..

Anyone know if any dp to hdmi 2.1 adapter other than cable matters works if all i want is 4k 120hz at 4:4:4?
I don't care about vrr for my use case, and vrr seems to be the reason people specifically use the cable matters one.
All i want is to use my rx6400 in linux while i use my 4090 in a windows vm for gaming, but i just can't use even desktop at 60hz anymore it feels so shit