8k60 8-bit rgb hdmi 2.1 from a 2080ti finally working!

mikeo

Gawd
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May 17, 2006
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Ordered one of these new sabrent usb-c to hdmi 2.1 adapters and can confirm it works at 8k60 8bit rgb out of the usb-c port on my zotac 2080ti. Figured i'd post a heads up on it since previously the only other option was the club 3d adapter that needs external power and is very glitchy.

https://www.amazon.com/dp/B08Y246V8X

Update: also works at 4k120 8bit rgb without having to mess with custom resolution tools.
 

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for that id rather get 65" LG CX and save 500 bucks
The CX isn't 8K. The ZX is, only goes down to 77", and it costs $20,000. LG's NanoCell LCD is currently $800 more than the Q800T.
 
I will say one of the downsides of 8k for desktop / photo / video work is you instantly see how low res a 24mp 6k photo sensor is. With that being said 8k raw video off an EOS R5 looks outstanding on it.
When you finally read a post that makes the memory in your case wince
 
Based on researching new receivers for my PC recently it seems to me like HDMI 2.1 needs another 6 months to a year before it's fully baked. In hind sight(apparently) the standard should have specified whether the signal should be compressed or uncompressed since they're incompatible.
 
Based on researching new receivers for my PC recently it seems to me like HDMI 2.1 needs another 6 months to a year before it's fully baked. In hind sight(apparently) the standard should have specified whether the signal should be compressed or uncompressed since they're incompatible.
This has been a massive headache for all early adopters, and really was fubar on launch. It's like they just wanted to get it out the door consumer be damned
 
How much bandwidth is 8K 120hz 10bit 4:4:4 ?
I assume hdmi 2.1 can't do it..
Uncompressed = 7680 hPixels * 4320 vPixels * 10 bpc * 3 channels * 120 Hz = 111.24 Gbps

HDMI 2.1 only supports up to 8K 60 Hz with DSC, as uncompressed is 55.62 Gbps. The data stream bandwidth available is 42.67 Gbps out of the total 48.
 
Uncompressed = 7680 hPixels * 4320 vPixels * 10 bpc * 3 channels * 120 Hz = 111.24 Gbps

HDMI 2.1 only supports up to 8K 60 Hz with DSC, as uncompressed is 55.62 Gbps. The data stream bandwidth available is 42.67 Gbps out of the total 48.
Dang so even DP 2.0 77Gbps can't even handle it. Going to be a looooong time before we see 8k uncompressed media.
 
I'm planning on doing a very similar setup, q800t with the same usb-c adapter on my 2080 super laptop so thanks for confirming it works. I'm on a samsung odyssey G9 (49" ultrawide) right now, I only game very occasionally and I do a lot of software development work so I expect/hope 8K would be far more useful for productivity.

I'm curious, does VRR work with that adapter? Is the latency ok for gaming on 8k?
 
I'm planning on doing a very similar setup, q800t with the same usb-c adapter on my 2080 super laptop so thanks for confirming it works. I'm on a samsung odyssey G9 (49" ultrawide) right now, I only game very occasionally and I do a lot of software development work so I expect/hope 8K would be far more useful for productivity.

I'm curious, does VRR work with that adapter? Is the latency ok for gaming on 8k?
Latency seems good to me, not sure on VRR.
 
Does the driver report it as a GSync-compatible device?
It's not listed on NVIDIA's list of compatible displays, but you can still force it in the control panel. Whether or not it actually works is a whole other question.
 
I received the sabrent adapter and also the q800t, didn't work with the end of Januari nvidia drivers I had installed but after updating the nvidia drivers to 466.27 (end of April) it worked immediately on 8k 60Hz.

Haven't done a lot of testing yet, it doesn't look like GSync works over the sabrent adapter but that might hopefully change with a driver update perhaps.
 
Ordered one of these new sabrent usb-c to hdmi 2.1 adapters and can confirm it works at 8k60 8bit rgb out of the usb-c port on my zotac 2080ti. Figured i'd post a heads up on it since previously the only other option was the club 3d adapter that needs external power and is very glitchy.

https://www.amazon.com/dp/B08Y246V8X

Update: also works at 4k120 8bit rgb without having to mess with custom resolution tools.
Can you please comment if chroma 4:4:4 is working with your setup in 8K 60hz? I have very similar adapter from Unitek (https://www.unitek-products.com/products/8k-usb-c-to-hdmi-2-1-adapter) which has the same chipset (RTD2173) as your Sabrent so performance shouldn't vary hopefully. I have mobile RTX 2070 and I was trying the exact same 65' Q800T in one store and without scaling 8K had black text with red ghosting so obviously it wasn't 4:4:4. From nvidia control panel there was only YCbCr422 available, but that made things much worse than RGB. Can this be some firmware or other issue that I can solve later, though I also tested one LG 8K TV with same result. I have the latest studio drivers. Thanks.
 
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Can you please comment if chroma 4:4:4 is working with your setup in 8K 60hz? I have very similar adapter from Unitek (https://www.unitek-products.com/products/8k-usb-c-to-hdmi-2-1-adapter) which has the same chipset (RTD2173) as your Sabrent so performance shouldn't vary hopefully. I have mobile RTX 2070 and I was trying the exact same 65' Q800T in one store and without scaling 8K had black text with red ghosting so obviously it wasn't 4:4:4. From nvidia control panel there was only YCbCr422 available, but that made things much worse than RGB. Can this be some firmware or other issue that I can solve later, though I also tested one LG 8K TV with same result. I have the latest studio drivers. Thanks.
I switched to a 3090 (finally found one in stock), so don't run that setup anymore.
 
I received the sabrent adapter and also the q800t, didn't work with the end of Januari nvidia drivers I had installed but after updating the nvidia drivers to 466.27 (end of April) it worked immediately on 8k 60Hz.

Haven't done a lot of testing yet, it doesn't look like GSync works over the sabrent adapter but that might hopefully change with a driver update perhaps.
Can you please check if chroma 4:4:4 is working for you? I know that Q800T supports it according to rtings.com, but I'm not sure if it's the limitation of the GPU (mobile RTX 2070) or the adapter based on my very limited experimence. Please see my latest post here as well. Thanks.
 
I switched to a 3090 (finally found one in stock), so don't run that setup anymore.
Thanks. I guess it was 4:4:4, because at least with no scaling it was hard not to notice it. Just trying to figure out if it's the limitation of the RTX 2070 or the adapter as the TV supports it just fine.
 
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