120hz appears less sharp at same resolution

[u/TheYungSheikh]

I tried to take a photo to show what I mean but it’s a bit hard to see. But at the exact same resolution, 120hz appears way less sharp than at 60. At 60, the quality is beautiful. I want to play at 120, but the quality is much worse. Is this due to lack of HDMI 2.1?

I’ve tried with and without HDR, VRR etc. In both 60 and 120, the TV says it’s the same resolution as well.

TV: Sony Bravia KD-55X9000H

PC: ASUS TUF Gaming B650M-Plus Wi-Fi CPU: AMD Ryzen 5 9600X GPU: ASUS Prime Radeon RX 9670 XT

[u/slowlybecomingsane]

You need hdmi 2.1 for 4k 120hz

[u/TheYungSheikh → u/slowlybecomingsane]

💔💔💔 I hope it comes ASAP

[u/HEY_beenTrying2meetU → u/TheYungSheikh]

why no display port?

[u/TheYungSheikh → u/HEY_beenTrying2meetU]

Connected to a TV, and I tried the displayport adapter thing and it doesn’t work

[u/CatsGoMooz → u/TheYungSheikh]

Hate to break it to ya but more than likely it won't happen. Its been a big issue for a while and HDMI refuses to let them implement it due to concerns about security of them exposes their closed source code.

I just recommend running the TV at 1440p 120hz tbh. That's what I do and games run better too and personally don't see a difference when sitting on couch.

Edit: Apparently I missed the fact they finally got HDMI to finally agree and it's being pushed out in Kernel 7.2.

[u/TheYungSheikh → u/CatsGoMooz]

I was about to say they’re adding it 😭 But I would do the 1440p 120hz but it’s not even an option in SteamOS

[u/Aggravating_Plan11 → u/slowlybecomingsane]

I thought the steam machines port was hdmi 2.1 capable it just wasn’t officially certified as 2.1 yet but the specs is there already

Edit: a quick google this is just the first article i found.

https://arstechnica.com/gaming/2025/12/why-wont-steam-machine-support-hdmi-2-1-digging-in-on-the-display-standard-drama/

The port is capable but linux is holding it back atm but valve are working on it so its just waiting a software patch.

[u/brunomarquesbr → u/slowlybecomingsane]

No, you don't need HDMI 2.1 anymore. Recently they managed to squeeze more info in the limited HDMI 2.0 bandwidth. I'm not going into detail here, but you can get 4k 120hz HDR with VRR over HDMI 2.0 (while giving up some minor color resolution) https://news.ycombinator.com/item?id=39544432

[u/Low_Excitement_1715 → u/brunomarquesbr]

DSC isn’t new. I was using it for several years. If you look at OP’s photos, that’s exactly what they were seeing. @OP a fix is coming. Once your distro updates the kernel to 7.2.0+ this issue will go away.

[u/Tepppopups]

Check if its RGB or YCbCr color in both modes. The second one uses less bandwidth, but has lower color resolution and may be a bit blurry with color fringing on sharp edges. It is used if your card, cable or monitor does not support higher bandwidth.

[u/Federal_Goose4545]

Yes it's due to the HDMI 2.0. HDMI 2.0 at 4k@120 is limited to 4:2:2 chroma subsampling, where as at 60 can do 4:4:4.

[u/SoLong_K]

Check your tv settings mate. Especially sharpening, depending on the algorithm, may act differently on different resolutions and refresh rates.

[u/TheYungSheikh → u/SoLong_K]

It seems it’s because of the lack HDMI 2.1 as people have mentioned. It compresses the image because it doesn’t have it. On my PS5 it looks great with the same TV settings at the same resolution and frame rate

[u/SoLong_K → u/TheYungSheikh]

Compression shouldn’t be that visible mate. Even in test environments, it shouldn’t be easy to spot. Many pc users use compression without even knowing it. I hope the new cable fixes your issue, but insufficient bandwidth usually ends up with a black screen, not with a low-quality image. As a last-one test, I suggest you connect the pc using the PS5 HDMI cable(just unplug it from the PS5 and plug it into your PC).

[u/TheYungSheikh → u/SoLong_K]

Yes, I used the same cable as my PS5 and it doesn’t make a difference :(

[u/SoLong_K]

Compression shouldn’t be that visable mate, even in test environments it shouldn’t be easy to spot. Many pc users uses compression without even knowing it. I hope new cable fix your issue but insufficient bandwidth usually end up black screen, not with low quality image. As last one test, I suggest you to connect the pc using the ps5 HDMI cable(just unplug it from PS5 and plug it to your PC).

[u/Vivid-Drink-5118 → u/SoLong_K]

hey mate, given this whole thread is about OP noticing the difference, it's fair to say the chroma subsampling is noticable ;)

[u/SoLong_K → u/Vivid-Drink-5118]

Yes mate, you’re right. I assumed It was DSC but it is not.

[u/Adventurous-Sun-1488 → u/SoLong_K]

Chroma subsampling is visible on small text, this is not DSC

[u/balrog687]

DSC?

[u/DerlisGs]

Apreta boton " home + A " y te sale el menu y abajo sale para subir la nitidez

[u/sammcj]

Looks like you're not using chroma 4:2:2 and have compression rather than raw 120hz 4K. For that you need hdmi 2.1 and kernel >=7.2 with the AMD patch for 120hz. If you're not comfortable with Linux or scripting I'd suggest that you might just have to wait for Steam to add support for it, if you are however you can patch it in a way similar to what I've done here: https://github.com/sammcj/steam-machine/blob/main/README.md

[u/gayboylover67]

RX 9670 XT ???

[u/LinkedHero]

Because no hdmi 2.1

[u/TheYungSheikh → u/LinkedHero]

Strange that it’s an option if it can’t even do it then

[u/LinkedHero → u/TheYungSheikh]

It just compresses the signal so it would fit in the bandwidth

[u/TheYungSheikh → u/LinkedHero]

Ah I see, thanks 🙏

[u/brunomarquesbr → u/LinkedHero]

No, actually you don't need it. Look https://www.reddit.com/r/SteamOS/s/lgGw6XY7pO

[u/LinkedHero → u/brunomarquesbr]

Exactly yes, it’s compressed. This doesn’t change anything