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MP All Models SOLVED: 8k Displays Running on Mac Pro? Any? What Video cards would work that support 8k HDMI 2.1/Displayport 1.4/2.0 displays on Mac Pro? YES you can

ZombiePhysicist said:
What Sabrent USBc to HDMI 2.1 device do you mean? Is it some adapter, or a cable? I found this one:

www.amazon.com

SABRENT USB Type C to HDMI 2.1 Adapter | 8K/60Hz & 4K/120Hz with DSC Function | 8K/30Hz & 4K Resolution Without DSC | Thunderbolt 3 Compatible (DA-UCH8)

SABRENT USB Type C to HDMI 2.1 Adapter | 8K/60Hz & 4K/120Hz with DSC Function | 8K/30Hz & 4K Resolution Without DSC | Thunderbolt 3 Compatible (DA-UCH8)
www.amazon.com

I didn't order a Sabrent, but did order this one:
www.amazon.com

Cable Matters 32.4Gbps USB C to DisplayPort 1.4 Adapter, 4K@240hz, 8K@60hz, and HDR Support -Thunderbolt 4 / USB4 Compatible with Oculus Rift S, iPad Pro, iPhone 16/15 Pro, MacBook Pro, XPS, Surface

The Cable Matters USB-C to DisplayPort Adapter connects a thin laptop with a USB-C or Thunderbolt 3 port to a monitor with DisplayPort. Experience the vibrant video and authentic audio supported by monitors with DisplayPort. Supports 8K, 4K and HD monitors at 60Hz. Thunderbolt 3...
www.amazon.com

and then figured Id try this cable in it:
www.amazon.com

CableDeconn DisplayPort 1.4 to HDMI 2.1 8K Cable 2 m Converter 8K @ 30Hz 4K @ 120Hz Directional Compatible with DisplayPort PC and HDMI Displays

source and display: Source:DisplayPort 1.4 Male Support Max Resolution Ultra HDMI 7680*4320 8K Display:HDMI 2.1 Male Max Support Resolution Ultra HDMI 7680*4320 8K It can max support 8K@30Hz 4K@120Hz Resolution in your external displays(HDTVs,Projectors,Monitors) Support copy and expansion ...
www.amazon.com

If you have one device that can kind of do it all, I'd be interested to know what it is.
Click to expand...
That’s the one.
Full specs here https://www.sabrent.com/product/DA-...r-8k-60hz-4k-120hz-with-dsc-function-da-uch8/

No caveats about Macs be hamstrung etc and Sabrent are a pretty reputable brand (I have some of their other devices like USB-C 5Gbps Ethernet adapter).

The fact it expressly talks about DSC gives me hope.
 
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I havent tried it. I didnt see anything there about a middle dispalyport conversion, but certainly is interesting. However, wonder if this is somehow better/different than just using a straight HDMI 2.1 port on my Mac Pro video card. It may be a necessary conversion "just because" the drivers on Mac are so not tailored to 8k yet. Might be worth a try.
 
I'm working on the basis that as Apple's 6K60 display works via DP 1.4 with DSC (Ref https://www.apple.com/pro-display-xdr/pdf/Pro_Display_White_Paper_Feb_2020.pdf) and an 8K60 signal fits in the same bandwidth, so maybe as the transport method is definitely supported by newish Mac's, then just bumping the resolution up that is sent over that supported transport isn't a huge ask. That being compared to native HDMI which Apple have no vested interest in supporting anything other than basic connectivity for business presentations it seems.

Note the adaptor says it requires "DisplayPort Alternate Mode". That plus the fact that HDMI Alt Mode never really got implemented by anyone and only supports up to HDMI v1.4b, so could not carry 8K60. So it has to do DP Alt Mode 1.4/DSC and then convert to HDMI 2.1 in the adaptor rather than HDMI Alt Mode 1.4b all the way through.

I've got a QE75QN900A in the lounge so I think I'll order the adaptor as it's cheap enough to take a risk on. If it works then I can select a TV for my office setup.
 
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ZombiePhysicist said:
I wonder, do you think if the tv had a DisplayPort 1.4 port, would the 8k image come through? And if so, doesn’t that mean the real issue is finding some cable/adapter that can push the right timings through. Although I’m confused why a straight hdmi 2.1 cable with 2.1 ports on both sides wouldn’t work. ?
Click to expand...
There is a guy here on the forum that said he got 8K@30hz over Displayport 1.4, hooking up the Dell 32" 8K monitor. So that means a TV with native Displayport could work in theory. I dont remember what hardware he had. There are very few TVs with Displayport, and they dont yet have 8K as far as I know. Only 4K. As explained before, I tried with a Displayport to HDMI 2.1 adapter and that didnt work with the AMD 6800.

There seams to be an issue with HDMI 2.1 on macOS or some of the graphics drivers. I would guess HDMI 2.1 is not yet supported. Also unclear if DSC is supported.

All in all, I dont see a solution for the moment to get 8K on a a large 8K TV using MacOS.
 
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Yep, 8K30 over DP 1.4 is known to work with MacOS.

Stacking adaptors rarely works. It may have been the combo didn't support DSC (a likely scenario IMO) which would definitely not have helped.

If I can 8K30 with 2xHiDPI I'll live with it. 8K60 would be nice though :)
 
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ZombiePhysicist said:
So I just ordered an 85" 8k display, so now I'm really motivated to make this work!

In searching around I came on to this post:
Click to expand...

This is a year old post. What I guess is that he also got a scaled down 8K to 4K signal to the TV, just like I get. The Mac itself reports 8K using e.g. SwitchResX) but the image is really just a 4K image with 8K text size. It doesnt look good.

It still makes sense to try the Cable Matters adapter. I tried Club 3D DP 1.4 to HDMI 2.1 CAC 1085. It does owkr, but as I described over. The MAD sends only a 4K signal even if the desktop is 8K. I suspect that the AMD driver or MacOS recognises that there is a HDMI display connected via DP 1.4, and therefore doesnt accept even 8k@30hz.

I consider trying the Cable Matter DP 1.4 to HDMI 2.1 adapter. Maybe it works differently that the Club 3D one.
 
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Pressure said:
AnandTech has a writeup about the Realtek RTD2173 chip used in that Sabrent adapter.

The Realtek chip uses DSC 1.2 to enable 8K@60Hz from DP1.4.
Click to expand...
I think the Club 3D CAC 1085 active adapter is using the Realtek chip. I have tried this, I'm not getting 8K using the adapter from the Mac with AMD 6800. Only 4K signal although the desktop is 8K.
 
JoseDB said:
Yep, 8K30 over DP 1.4 is known to work with MacOS.
Click to expand...

Yes I read that someone got 8K@30hz on the Dell 32 inch 8K monitor using only a single DP cable. I.e. no HDMI 2.1 involved nor DSC. Curious what version of MacOS and what graphics chip was used.
 
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Pressure said:
AnandTech has a writeup about the Realtek RTD2173 chip used in that Sabrent adapter.

The Realtek chip uses DSC 1.2 to enable 8K@60Hz from DP1.4.
Click to expand...
They also discuss DP 1.4 / HDMI 2.1 adapters at this thread: Mac mini: 4k @ 120hz?
forums.macrumors.com

Mac mini: 4k @ 120hz?

Any thoughts on using something like this to emulate a Displayport device, forcing the Mac to output a full signal then adding on a DP to HDMI 2.1 Active Adapter on the output? https://www.ute.de/produkte/videotechnik/edid-emulatoren/nti-dp-hp-mntr-src.html
forums.macrumors.com forums.macrumors.com
 
"MacOS incorrectly limiting pixel clock to 600mhz on Display Port 1.4 to HDMI 2.1 adapters, preventing 4k120"
forums.macrumors.com

Mac mini: 4k @ 120hz?

My report to Apple - please let me know anything I've missed or got wrong! MacOS incorrectly limiting pixel clock to 600mhz on Display Port 1.4 to HDMI 2.1 adapters, preventing 4k120 Description of the problem: Unable to display 4k120 on an external HDMI 2.1 display via a Displayport 1.4 to...
forums.macrumors.com forums.macrumors.com

Here is the post about a possible limitation with MacOS.
 
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Arvine said:
"MacOS incorrectly limiting pixel clock to 600mhz on Display Port 1.4 to HDMI 2.1 adapters, preventing 4k120"
forums.macrumors.com

Mac mini: 4k @ 120hz?

My report to Apple - please let me know anything I've missed or got wrong! MacOS incorrectly limiting pixel clock to 600mhz on Display Port 1.4 to HDMI 2.1 adapters, preventing 4k120 Description of the problem: Unable to display 4k120 on an external HDMI 2.1 display via a Displayport 1.4 to...
forums.macrumors.com forums.macrumors.com

Here is the post about a possible limitation with MacOS.
Click to expand...

interesting. I know generally stacking adapters messes things up, but here, there is a tiny chance it could help. The reporting of the 60o hz clock makes Mac OS work wrong, I wonder if one of the links fails to report that correctly somehow, would it “trick” the connection to work? It will likely fail but worth a shot to try it.
 
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Pressure said:
That's me.

I'm currently using Catalina (10.15.7) and using the Radeon Vega Frontier Edition (16GB HBM).
Click to expand...
So this card:
www.amd.com

Radeon™ Vega Frontier Edition Graphics

Unlock the potential of Radeon™ Vega frontier edition graphics card for workstation. Specs include 64 next gen compute units, 13.1 TFLOPS & opencl 2.0 support.
www.amd.com www.amd.com
www.amd.com

Radeon™ Vega Frontier Edition (Air-cooled)

Visit AMD to learn about the prices, technologies, specifications and features of the Radeon™ Vega Frontier Edition (Air-cooled) professional graphics card.
www.amd.com www.amd.com

It has 3 DisplayPort 1.4 and one hdmi 2.0 ports if I read it correctly.

can you tell us:

1 what port you’re using on the card,
2 what cables you’re using to connect to the display,
3 and what port on the display you’re connecting to?

thanks so much.
 
ZombiePhysicist said:
So this card:
www.amd.com

Radeon™ Vega Frontier Edition Graphics

Unlock the potential of Radeon™ Vega frontier edition graphics card for workstation. Specs include 64 next gen compute units, 13.1 TFLOPS & opencl 2.0 support.
www.amd.com www.amd.com
www.amd.com

Radeon™ Vega Frontier Edition (Air-cooled)

Visit AMD to learn about the prices, technologies, specifications and features of the Radeon™ Vega Frontier Edition (Air-cooled) professional graphics card.
www.amd.com www.amd.com

It has 3 DisplayPort 1.4 and one hdmi 2.0 ports if I read it correctly.

can you tell us:

1 what port you’re using on the card,
2 what cables you’re using to connect to the display,
3 and what port on the display you’re connecting to?

thanks so much.
Click to expand...
There's not a lot of options. The answers are probably:
1: DisplayPort 1.4 output
2: DisplayPort 1.4 cable
3: DisplayPort 1.4 input

The Vega doesn't support DSC. The Dell UP3218K doesn't support DSC input.
 
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joevt said:
There's not a lot of options. The answers are probably:
1: DisplayPort 1.4 output
2: DisplayPort 1.4 cable
3: DisplayPort 1.4 input

The Vega doesn't support DSC. The Dell UP3218K doesn't support DSC input.
Click to expand...

Thanks that helps. It looks like macOS is pretty cool with a pure DisplayPort setup, and a ****show with HDMI2.1. :/

Isnt there some mode, even via HDMI2.0 that gives you 8k? Is it like 8k@30hz maybe with some kind of compression or lowered subsampling? I know DSC doesnt work with HDMI2.0 but maybe there is some lowered settings that get you to at least 8k@30 over the supported HDMI2.0?

linustechtips.com

Can you run 4K at 120hz on HDMI 2.0 Port?

Hello, with the next gen consoles coming out I’ve heard they’ll be able to support 4K at 120hz. Is this combination possible to hit with an HDMI 2.0 port? I’ve heard mixed things about the subject so please advise. Thank you so much for your guys’s help.
linustechtips.com linustechtips.com
Yes, but only if you give up on chroma subsampling 4:4:4. 4:2:0 should be able to do 4k120 at the cost of a worse image quality.
Click to expand...

I may be wrong, but I think 4k@120 takes up roughly the same bandwidth as 8k@30.
 
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4:2:0 8bpc is basically 12bpp (4:2:0 is 12 components per 8 pixels which normally has 24 components)
With the bandwidth of HDMI 2.0, that's enough to get 4K120 or 8K30. You just need an OS driver, GPU, and display that will support it.
 
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ZombiePhysicist said:
So this card:
www.amd.com

Radeon™ Vega Frontier Edition Graphics

Unlock the potential of Radeon™ Vega frontier edition graphics card for workstation. Specs include 64 next gen compute units, 13.1 TFLOPS & opencl 2.0 support.
www.amd.com www.amd.com
www.amd.com

Radeon™ Vega Frontier Edition (Air-cooled)

Visit AMD to learn about the prices, technologies, specifications and features of the Radeon™ Vega Frontier Edition (Air-cooled) professional graphics card.
www.amd.com www.amd.com

It has 3 DisplayPort 1.4 and one hdmi 2.0 ports if I read it correctly.

can you tell us:

1 what port you’re using on the card,
2 what cables you’re using to connect to the display,
3 and what port on the display you’re connecting to?

thanks so much.
Click to expand...
It's a pure DP1.4 setup, as @joevt mentions above. It doesn't matter what DP1.4 input or output I pick on the graphic card or monitor. Single cable DP 1.4 will display 8K@30Hz.
ZombiePhysicist said:
BTW I think you ran scripts to get you setup to work? This might be helpful:

www.macworld.com

This M1 Mac display hack is a must for 1440p monitors

On M1 Macs, Apple doesn't provide proper Retina scaling options for 1440p monitors. BetterDummy provides a workaround.
www.macworld.com www.macworld.com
Click to expand...
It's working fine now at 8K@60Hz using both DP 1.4 cables and enabling HiDPI with a script.
 
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mattspace said:
Is it treating the display as a single display, or is it acting like two portrait displays, with a menu on only one of them?
Click to expand...
It's treating it as two 3840x4320 displays (1920x2160 HiDPI) so the top menu is only on half the screen but I use auto-hide on it.

It baffles me that Apple just doesn't care more about monitor support. It seems like an easy fix.

The alternative is 8K@30Hz with a single cable.
 
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Pressure said:
It baffles me that Apple just doesn't care more about monitor support. It seems like an easy fix.
Click to expand...
They definitely know the UP3218K exists because they’ve added a pointless override file for it (I apologise if this is old news to you). I guess they want people to get the XDR instead.
 
XDR is overpriced crap. But you may well be right. It’s perplexing how resistant they are to 8k for a while now.
 
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