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Love-hate 🍏 relationship

macrumors 68040
Original poster
Sep 19, 2021
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using a usb-c/tb3-4 to HDMI 2.1 adapter it seems you still can't have HDMI 2.1(4k120) to work

is it the case for m1/pro/max only or even Intel macs have such a limitation?

do you reckon it's something apple may fix/allow if Enough people report it ? I mean historically has apple ever fixed SW/fw mistakes (assuming it's not a physical limitation of the M1 chip )
 

hovscorpion12

macrumors 68040
Sep 12, 2011
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USA
It is actually a physical limitation. Both the 14" and 16" were built with HDMI 2.0. You can use an HDMI 2.1 cable, but due to the hardware itself, you will be limited to 60hz
 

fa8362

macrumors 68000
Jul 7, 2008
1,571
498
again,you're saying that the usb-c thunderbolt ports aren't able to provide enough bandwidth for what HDMI 2.1 requires
No. I'm saying that 2.0 is incapable of the ELECTRONIC COMMUNICATION SIGNALING required for HDMI 2.1. They are different protocols. The receiving end sees the 2.0 signaling, not the required 2.1 signaling and blocks access.
 

Love-hate 🍏 relationship

macrumors 68040
Original poster
Sep 19, 2021
3,058
3,237
No. I'm saying that 2.0 is incapable of the ELECTRONIC COMMUNICATION SIGNALING required for HDMI 2.1. They are different protocols. The receiving end sees the 2.0 signaling, not the required 2.1 signaling and blocks access.
cool thank u
my question however never involved the HDMI port but instead the thunderbolt ones ,which I wanted to use with an adapter
 

Love-hate 🍏 relationship

macrumors 68040
Original poster
Sep 19, 2021
3,058
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The port is irrelevant. Apple licensed HDMI 2.0, not 2.1. 2.1 is not authorized, so it won't work, regardless of port.
oh i hadnt got you .

do you have a source for that or is it a deduction from the ports apple effectively put in the mbp ?

the hdmi 2.0 port seems to be recycled from the mac mini,i didnt extrapolate anything else
 

fa8362

macrumors 68000
Jul 7, 2008
1,571
498
oh i hadnt got you .

do you have a source for that or is it a deduction from the ports apple effectively put in the mbp ?

the hdmi 2.0 port seems to be recycled from the mac mini,i didnt extrapolate anything else
Google it. Tons of sources.
 

hovscorpion12

macrumors 68040
Sep 12, 2011
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To answer the question again. No. There is no software that can be used to give you 4K/120hz. The MacBook Pro 14” and 16” are hardware coded to HDMI 2.0.

The Mac Mini HDMI port is limited to 4K/60 as well. There is currently no Mac Product that ships with HDMI 2.1.

it is not possible to make an HDMI 2.0 to function as an HDMI 2.1


 

apparatchik

macrumors 6502a
Mar 6, 2008
889
2,709
Interesting, in general (let's forget about Macs) is thunderbolt 4 / USB 4 not capable of doing HDMI 2.1 through an adapter? is the bandwidth too narrow?

ATM I have both HDMI and Ethernet adapters, but never pictured thunderbolt 4 of having insufficient bandwidth for having HDMI 2.1, also, every HDMI 2.0 port automatically becomes 2.1 for newly release devices, due to how the protocol licensing and naming works, regardless of actual feature subset.

I suspect though, that when Apple releases an HDMI 2.1 port device it will try to support most of the functionality, as they might get a backlash otherwise.
 

hovscorpion12

macrumors 68040
Sep 12, 2011
3,048
3,130
USA
Interesting, in general (let's forget about Macs) is thunderbolt 4 / USB 4 not capable of doing HDMI 2.1 through an adapter? is the bandwidth too narrow?

ATM I have both HDMI and Ethernet adapters, but never pictured thunderbolt 4 of having insufficient bandwidth for having HDMI 2.1, also, every HDMI 2.0 port automatically becomes 2.1 for newly release devices, due to how the protocol licensing and naming works, regardless of actual feature subset.

I suspect though, that when Apple releases an HDMI 2.1 port device it will try to support most of the functionality, as they might get a backlash otherwise.
If a computer is equipped with a 2.1 port, a thunderbolt 4 cable/hub/adapter will take full advantage of available bandwidth and provide over 60hz ability while so driving a higher display resolution.

Your second point of 2.0 being automatically being 2.1 is incorrect. Each port is hard coded to meet the industry standard of that port.

HDMI 2.1 supports 48GB bandwidth with a Ultra High Speed HDMI Cable. It can drive 8K60 and 4K120, and resolutions up to 10K.

HDMI 2.0 only supports 18GB of bandwidth.

Once Apple releases their ProDisplay XDR with 120hz, Apple will release Macs with HDMI 2.1 ports which will fully support all 2.1 standards.
 

apparatchik

macrumors 6502a
Mar 6, 2008
889
2,709
If a computer is equipped with a 2.1 port, a thunderbolt 4 cable/hub/adapter will take full advantage of available bandwidth and provide over 60hz ability while so driving a higher display resolution.

Your second point of 2.0 being automatically being 2.1 is incorrect. Each port is hard coded to meet the industry standard of that port.

HDMI 2.1 supports 48GB bandwidth with a Ultra High Speed HDMI Cable. It can drive 8K60 and 4K120, and resolutions up to 10K.

HDMI 2.0 only supports 18GB of bandwidth.

Once Apple releases their ProDisplay XDR with 120hz, Apple will release Macs with HDMI 2.1 ports which will fully support all 2.1 standards.

My understanding was that 2.1 comprises a set of features of which manufacturers may implement just a few or none at all, but maybe this applies just to the display part of the combo and not the source, is that right?

Also, if you have a thunderbolt 4 port, what’s blocking you from a HDMI 2.1 adapter? most Macs don’t even have HDMI ports at all, like the MBA, but they do have TB 4, so what’s the limitation here?
 
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fa8362

macrumors 68000
Jul 7, 2008
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My understanding was that 2.1 comprises a set of features of which manufacturers may implement just a few or none at all, but maybe this applies just to the display part of the combo and not the source, is that right?

Also, if you have a thunderbolt 4 port, what’s blocking you from a HDMI 2.1 adapter? most Macs don’t even have HDMI ports at all, like the MBA, but they do have TB 4, so what’s the limitation here?
It's already been explained.
 

Ethosik

Contributor
Oct 21, 2009
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jdb8167

macrumors 601
Nov 17, 2008
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It's already been explained.
Not adequately. Since the M1 Pro and Max MacBook Pro notebooks are Thunderbolt 4 certified that means that they should be able to use DisplayPort 2.0 since that is part of the TB4 specification. DP2.0 has 80 Gbps bandwidth more than enough for 4k@120Hz. It might be that the required DP2.0->HDMI 2.1 adapters don't exist yet.

Edit: After a little more searching, it isn't clear if TB4 requires DisplayPort 2.0 or just that it optionally supports it. I can't find anything definitive.

Edit2: There is at least one company with a DisplayPort 2.0 to HDMI 2.1 protocol converter. I don't know if there are any released products around it yet. Parade Technlogy: PS196
 
Last edited:

briko

macrumors regular
Oct 20, 2015
116
422
Apparently the thunderbolt 4 ports are physically capable of displaying 4K@120hz. They can convert DisplayPort 1.4 to HDMI 2.1 with an appropriate adapter. However, this is prevented in software by macOS.

It’s been reported that recent Intel macs can output 4K@120 using Windows under Bootcamp. So the hardware is there, but not the software when running macOS.

I’m no expert on this. I’m just summarizing a bit of what I read in this thread:

 

apparatchik

macrumors 6502a
Mar 6, 2008
889
2,709
Apparently the thunderbolt 4 ports are physically capable of displaying 4K@120hz. They can convert DisplayPort 1.4 to HDMI 2.1 with an appropriate adapter. However, this is prevented in software by macOS.

It’s been reported that recent Intel macs can output 4K@120 using Windows under Bootcamp. So the hardware is there, but not the software when running macOS.

I’m no expert on this. I’m just summarizing a bit of what I read in this thread:


If they can do it under Windows then there’s no hardware or electrical limitation preventing them from it, I really don’t get why TB4 Macs without any type of HDMI port or license or certification cannot have an HDMI 2.1 adapter.

You have TB4, therefore an adapter can be made that does TB4 -> DP -> HDMI 2.1 if the software allows for it, doesn’t it?
 

BeatCrazy

macrumors 603
Jul 20, 2011
5,137
4,516
using a usb-c/tb3-4 to HDMI 2.1 adapter it seems you still can't have HDMI 2.1(4k120) to work

is it the case for m1/pro/max only or even Intel macs have such a limitation?

do you reckon it's something apple may fix/allow if Enough people report it ? I mean historically has apple ever fixed SW/fw mistakes (assuming it's not a physical limitation of the M1 chip )

Ignore the haters! You can do this :)

You do need an Intel Mac with Thunderbolt 3. Connect an eGPU like the Razer Core X. Add an appropriate GPU with HDMI 2.1 support, like an AMD RX-6800. BOOM!
 

Love-hate 🍏 relationship

macrumors 68040
Original poster
Sep 19, 2021
3,058
3,237
Ignore the haters! You can do this :)

You do need an Intel Mac with Thunderbolt 3. Connect an eGPU like the Razer Core X. Add an appropriate GPU with HDMI 2.1 support, like an AMD RX-6800. BOOM!
well pity I got an m1 then lol

I tried searching about HDMI 2.1 licensing as the other dude said and I haven't found anything like that .

do u have any idea why it's not available on m1 /Intel without dircetey graphics card?
 

Erasmus

macrumors 68030
Jun 22, 2006
2,756
300
Australia
Really hoping this gets fixed. Even if I never actually use it, the new MBPs certainly have the power to run 120Hz 4K or even more. Whether it's TB4 to DP 1.4 with DSC, or preferably TB4 to DP 2.0 and/or HDMI 2.1, monitors and TV screens at 4K 120Hz or 8K 60Hz are becoming more common, and are at actually attainable prices already.
 
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