DP/USB-C/Thunderbolt to HDMI 2.1 4k@120hz RGB4:4:4 10b HDR with Apple Silicon M1-M4 now possible !

[dinosauradventure]

Thanks all for your work on this. I’ve submitted more feedback to Apple and emailed Tim Cook. I believe this limitation is intentional to drive sales of Apple displays. It is anticompetitive and may be a violation of the EU digital markets act, which I stated in my messages. I would encourage you all to do the same, probably won’t change anything but worth a try.

If there’s no fix before the holiday return window ends, I’ll likely return my new mini. Sad!

 

[Zorast]

Thanks all for your work on this. I’ve submitted more feedback to Apple and emailed Tim Cook. I believe this limitation is intentional to drive sales of Apple displays. It is anticompetitive and may be a violation of the EU digital markets act, which I stated in my messages. I would encourage you all to do the same, probably won’t change anything but worth a try.

If there’s no fix before the holiday return window ends, I’ll likely return my new mini. Sad!

Plz share ure apple feedback ID so we can reference it.

 

[dinosauradventure]

Feedback ID: FB15750642

 

[Zorast]

Feedback ID: FB15750642

I reference this also in OP

 

[eret9616]

What about using a DP to Type-C converter instead of HDMI? Does it support 4K at 120Hz?

 

[Divinehymn]

I tried to modify my MOSHOU cable with CM Firmware 4k 120hz 4-4-4 HDR 201310 for VMM7100 USB-C > HDMI, unable to detect EDID after firmware update, not sure if apple silicone updated some trick by this time， still looking for a solution

 

[Zorast]

What about using a DP to Type-C converter instead of HDMI? Does it support 4K at 120Hz?

DP always works without any workaround

 

[waydabber]

@AironMan - I don't think this is in any way malicious on Apple's part, more like a kind of simplified approach to things. The M4 mini seems to behave the way older Macs did, except when certain ultrawide, 6K or 8K displays are connected - in which case (to comply with specs) the logic that populates display modes probably goes to a different path. Since this behavior is ok for most users and fulfills the advertised capabilities, it's probably fine by their standards, especially for an initial rollout. Apple engineers might feel that it does not make sense to have HiDPI resolutions available beyond a certain scale and certainly not at a native resolution level (which produces only a 2x supersampling), despite the fact that some users want this feature. Hopefully this will be tweaked in the future.

Also, there might be other factors there, like a balancing act - if the system thinks a display would not benefit much from some higher resolution options, it just does not provide that in case an other display is connected later on which needed that resource. This is because these Macs support different resolutions and refresh rates depending on the number and type of displays connected (see the specs - it can do 3x6K or 1x8K+1x6K). Obviously the system does not know the user's intent in advance about what kind of displays will be connected later on - so it is trying to be as economical as possible (since if 8K resources are granted to a connection unnecessarily, the user could later on connect 1 less external display).

 

[Zorast]

@AironMan - I don't think this is in any way malicious on Apple's part, more like a kind of simplified approach to things. The M4 mini seems to behave the way older Macs did, except when certain ultrawide, 6K or 8K displays are connected - in which case (to comply with specs) the logic that populates display modes probably goes to a different path. Since this behavior is ok for most users and fulfills the advertised capabilities, it's probably fine by their standards, especially for an initial rollout. Apple engineers might feel that it does not make sense to have HiDPI resolutions available beyond a certain scale and certainly not at a native resolution level (which produces only a 2x supersampling), despite the fact that some users want this feature. Hopefully this will be tweaked in the future.

Also, there might be other factors there, like a balancing act - if the system thinks a display would not benefit much from some higher resolution options, it just does not provide that in case an other display is connected later on which needed that resource. This is because these Macs support different resolutions and refresh rates depending on the number and type of displays connected (see the specs - it can do 3x6K or 1x8K+1x6K). Obviously the system does not know the user's intent in advance about what kind of displays will be connected later on - so it is trying to be as economical as possible (since if 8K resources are granted to a connection unnecessarily, the user could later on connect 1 less external display).

The problem here is that it does work with 14.0, and they are limiting it in the next release! So they’re undoing a function that worked before! This is the problem I have with Apple in their feature list—this must be something they want to do. Why remove a function that already works? That does not make sense to me! It’s like you disable a function in BetterDisplay that you know people needed in the past, and now you ignore it and disable it in the next version without naming it in the changelog?? Holy sh…, for me it’s a big thing because it has a lot of impact for pro users. Another thing is the HDR disable function—how can you explain why it was changed so that it only affects non-Apple displays? I think you see it too neutrally; to me, it’s very clear what Apple is trying to do here.

In fact, with with macOS 14.0 it works nice, after released versions they limit more and more..

 

[waydabber]

Sorry, I was talking about the M4 (which does not support 14.0 - so that is not a reference point in its case). I don't have a clear explanation about the additional limitations for older Macs - but for the M4 limiting to 6K when 8K is not absolutely necessary makes sense looking at the specs and the dynamic way M4 seems to allocate resources in a way that allows 3 displays to be potentially connected.

I think the most plausible explanation for the changes affecting older Apple Silicon Macs is that the changes implemented for more recent Macs simply (needlessly) affect those as well - to keep the entire logic simplified and universal among generations.

Anyway, my main point is that this seems to be more like an engineering decision, not something that is driven by sales/marketing considerations. Still, it is useful to provide feedback and maybe the engineering team will further fine-tune things.

 

[Zorast]

Sorry, I was talking about the M4 (which does not support 14.0 - so that is not a reference point in its case). I don't have a clear explanation about the additional limitations for older Macs - but for the M4 limiting to 6K when 8K is not absolutely necessary makes sense looking at the specs and the dynamic way M4 seems to allocate resources in a way that allows 3 displays to be potentially connected.

I think the most plausible explanation for the changes affecting older Apple Silicon Macs is that the changes implemented for more recent Macs simply (needlessly) affect those as well - to keep the entire logic simplified and universal among generations.

Anyway, my main point is that this seems to be more like an engineering decision, not something that is driven by sales/marketing considerations. Still, it is useful to provide feedback and maybe the engineering team will further fine-tune things.

Yes, what you say does make sense, but this is a really simple way to handle it. Apple is a worldwide bestselling company—why not spend a little more time on its so-called PRO devices for PRO users? We are not talking about the MacBook Air; I’m on a MAX, and the M4 Pro also has this problem. I understand the logic you pointed out, but this is not the correct way to approach it. If they knew in the past that it was needed, they can’t remove it without any changelog for that. The clearest issue is HDR with HiDPI since 14.1, which only affects non-Apple displays.

 

[waydabber]

I don't have a clear explanation for the HDR issue at higher refresh rates. Probably one of the devices have an issue with HDR at higher framebuffer pixel clock rates, acting as a constraint that affects all other Macs in an unified logic. This might explain the retroactive change. But this theory is somewhat discredited by the fact that some Macs seem not to have this limitation. So I don't know. Probably the code that manages all this is not as neat internally as one might hope but actually looks like any other code that is being reused, patched, tweaked this way and that over the years, incorporating compatibility with newer and newer models with differing capabilities...

 

[Zorast]

I don't have a clear explanation for the HDR issue at higher refresh rates. Probably one of the devices have an issue with HDR at higher framebuffer pixel clock rates, acting as a constraint that affects all other Macs in an unified logic. This might explain the retroactive change. But this theory is somewhat discredited by the fact that some Macs seem not to have this limitation. So I don't know. Probably the code that manages all this is not as neat internally as one might hope but actually looks like any other code that is being reused, patched, tweaked this way and that over the years, incorporating compatibility with newer and newer models with differing capabilities...

Yess ORRRR they want us to force buy Apple Monitors without OLED and 120hz

 

[kasakka]

I don't have a clear explanation for the HDR issue at higher refresh rates. Probably one of the devices have an issue with HDR at higher framebuffer pixel clock rates, acting as a constraint that affects all other Macs in an unified logic. This might explain the retroactive change. But this theory is somewhat discredited by the fact that some Macs seem not to have this limitation. So I don't know. Probably the code that manages all this is not as neat internally as one might hope but actually looks like any other code that is being reused, patched, tweaked this way and that over the years, incorporating compatibility with newer and newer models with differing capabilities...

If I've learned anything about Apple, it's that they don't seem to test on anything but their own monitors. There's just so many weird anomalies I've encountered with other brands on MacOS that just don't exist on Windows.

I use the Samsung G95NC 8Kx2K superultrawide on a M2 Max MBP, split using Picture by Picture mode to 5120x2160 + 2560x2160. The 2560x2160 is well within any Mac's display capabilities, yet MacOS has a lot of difficulty correctly detecting it when coming out of sleep. Sometimes it works, sometimes it gets thrown to mirroring mode, sometimes it's detected as 1920x1080. If I split the display as 4K + 4K, these issues seem to go away because it's a more standard resolution.

I even had 4K flickering issues with a HDMI 2.1 cable on my M2 Max MBP 16", that completely went away when I connected the exact same cable to my desktop PC's Nvidia GPU.

And this is without involving any USB-C to HDMI 2.1 adapters.

 

[abe17]

Really good news guys! I got an CableMatters Hub with USB-C PD, HDMI, 1Gbit Ethernet, 2x USB-A 3.0 that can be directly flashed to get 4k@120 YCBCR4:4:4 HDR. This will also solve all standby issue because its an active one. The Firmware ONLY FOR THIS MODEL are attached. I will update the OP with that new one.

The hub is this one:

Model-Number Cable Matters 201310

USB-C Multiport Adapter with 8K HDMI, 2x USB 3.0, Gigabit Ethernet, and Power Delivery

Transform a single USB-C port into a video, peripheral, and charging powerhouse with the Cable Matters USB-C Multiport Adapter with 8K HDMI and Power Delivery

www.cablematters.com

Hi There.

I have an issue while flashing my CableMatters Hub HDMI 2.1 to USB C (VMM 7100 model) with this firmware.
and this is all my fault because didn't read all the thread carefully.

It comes after I flashed my Hub with windows laptop, and actually I just downgrading the Firmware version from 7.02.123 to 7.02.112, then I got my resolution limited to 4k@30hz. (before this, i can have 4k@60hz with the latest firmware)


Then everything is just getting worst after realizing that I haven't the FW backup.
I come to the thread on this forum, and see that your thread attaching the firmware on latest date.

I Installed it, got the warning about “product id didn't match and the firmware was for a different board", just click ok (because on PDF says that), and then my CableMatters Hub is just die.

It cannot be detected as an Input, both on Win and Mac.
when i try to use VMM flash tool, (to recover / troubleshoot) there is an error message says cannot find synaptics MST DP hub IC

Is there anything I can do?
Please I really need your help guys

 

[acrylicus]

This is really crazy! I dont understand Apple at all.

So the M3 can output 4k@120hz HDR+HiDPI but the M4 does not ?

I am on an M3 and cannot consistently get 4k@120hz working. Sometimes after hours it works, then I reboot or undock/redock and it goes back to being 60hz.

 

[acrylicus]

LG OLED C4 42"
MacBook Pro M1 Max
Cable Matters 48Gbps USB C to HDMI 2.1

Getting
3200x1800@120Hz (Max available) with HiDPI and HDR
or
3840x2160@120Hz with HiDPI no HDR

with trick described before.

What is the "trick described before" here ???

 

[iambk]

Has anyone had better luck with the

Cable Matters 48Gbps USB C to HDMI 2.1 Adapter (201388)​

than the

Cable Matters 48Gbps 8K USB C to HDMI 2.1 Cable (201362)​

or had better luck with the newer cable

Cable Matters USB C to HDMI 2.1 Cable (201392)​

I bought the 201362 because a cable seemed a lot nicer than a dongle/adapter hanging off my Macbook M1 Pro. On my LG C4, it works best on HDMI2 (eARC) where I can usually get 8gbps per lane, but 3L6 (3 lanes 6gbps) tends to be more reliable against all ports. This limits me to 60Hz 10bpp or 120Hz 8bpp in 4:4:4.

With my LG G3, it doesn't want to do anything other than TM (HDMI 2.0 / TMDS-Transition Minimised Differential Signaling) with very rare exception.

I also have a Dell HD22Q Dock. Using the Dell Dock (with BetterDisplay) and a new HDMI 2.1 cable, I'm able to get 4L10 (4 lanes 10gbps) without any fuss on my C4 much like OP in this post:

https://www.reddit.com/r/UsbCHardware/comments/17fk7kb

Maybe I should have bought the adapter and my life would have been easier? Is anything with the VM7100 just kind of fussy?

Cable Matters support is great, but I just want a cable that works well. I've already purchased BetterDisplay.

Even if I were to eventually get an M3 Pro or M4 Pro, they only come with a single HDMI 2.1 port and I have 2 displays to drive. HDMI 2.0 will work for native 4K 4:4:4 8bpp RGB, but it's nice to have 10bpp and HDR options, which HDMI 2.0 can't quite handle.

 

[iMac&Cheese]

Just wanna ask if at 4k 144hz using USB-C (DP alt mode), it also supports 10-bit depth RGB444.

I have an M1 Pro MBP & am looking to buy M28U monitor

 

[TaFe]

Trying my luck here after no success on AVSForums/Reddit as it seems my issue might be connected to what's discussed here (apologies if it isn't): I have a 2023 MacBook Pro M2 Max which is advertised as capable of driving 8k displays via its HDMI 2.1 output. Yet when I connect the MBP to my JVC NZ7 projector (which is advertised to use native 8k input on its HDMI 2.1 port and I have seen pictures from PC users being able to output 8k/60 to it), the MBP only shows up as a 4k input and the computer shows the projector as a 4k only device. I have purchased the certified ultra high speed 6 feet HDMI cable Apple advises to get to make sure it wasn't my other (also HDMI 2.1 48gbps certified!) cables I had causing the issue and also went directly into the projector instead of running it through a receiver but no luck. I can easily output 4k/120Hz to the projector (including 4k/120 in HDR), but no 8k option is shown in the Display setting menu at all on the MBP, even when I manually put the refresh rate on the MBP down to 60Hz or even 30Hz (tried both with or without HDR).

Thanks in advance on any advice as to how to solve this.

 

[Zorast]

Just wanna ask if at 4k 144hz using USB-C (DP alt mode), it also supports 10-bit depth RGB444.

I have an M1 Pro MBP & am looking to buy M28U monitor

I think some guys does confirm that. But not sure, search in the thread for that

 

[Zorast]

What is the "trick described before" here ???

Read the OP plz.

here's the solution

https://forums.macrumors.com/threads/dp-usb-c-thunderbolt-3-4-to-hdmi-2-1-4k-120hz-rgb4-4-4-10b-hdr-with-apple-silicon-m1-m2-m3-now-possible.2381664/post-33523352

 

[waydabber]

@Zorast - the latest BetterDisplay "internal pre-release" version (to get it, enable both `Receive pre-release updates` and `Receive internal pre-release updates` under Settings > Application > Updates) should have an improved configuration protection for this unexposed refresh rate trick. Let me know if this does not work as expected.

UPDATE: This still does not work as expected (as I am now testing it on a M1 Pro with 4K@120Hz display). Will tweak it further.

 

[dk46359]

Hi There.

I have an issue while flashing my CableMatters Hub HDMI 2.1 to USB C (VMM 7100 model) with this firmware.
and this is all my fault because didn't read all the thread carefully.

It comes after I flashed my Hub with windows laptop, and actually I just downgrading the Firmware version from 7.02.123 to 7.02.112, then I got my resolution limited to 4k@30hz. (before this, i can have 4k@60hz with the latest firmware)


Then everything is just getting worst after realizing that I haven't the FW backup.
I come to the thread on this forum, and see that your thread attaching the firmware on latest date.

I Installed it, got the warning about “product id didn't match and the firmware was for a different board", just click ok (because on PDF says that), and then my CableMatters Hub is just die.

It cannot be detected as an Input, both on Win and Mac.
when i try to use VMM flash tool, (to recover / troubleshoot) there is an error message says cannot find synaptics MST DP hub IC
View attachment 2451408


Is there anything I can do?
Please I really need your help guys

I got the same error and was able to fix it. But (and it is a HUGE BUT) it was not easy. The "short" version:

1. You need to have a laptop that supports DP alt mode over usbc. I used an older windows laptop that was able to show/mirror the laptop screen when connected to the TV via usbc. But the flash resulted in the error and effectively "bricked" the adapter as it would not connect/display. I ended up downloading Parallels Desktop on my M1 MBP and got it to work that way.

2. Use the cable matters knowledge board instructions, https://kb.cablematters.com/index.php?View=entry&EntryID=147

3. You need to be comfortable going in and modifying text files in the Firmware Update Tool. There is a table "VMM_Firmware_Table.txt" that effectively tells the application what firmware fullrom to apply (located in bin). I figured I can't break the adapter any more than it is already is so I went in and tried different combinations until it worked.

4. I was not expecting my trial/error to work so I don't have it documented. I do remember having to pick one of the older "fullroms" to get the adapter displaying again. Once I got to that point, I was able to follow the instructions at the above link and it worked. I'm 99% sure it installed the "Spyder_fw_DP_CM_MBP4k120.fullrom" version.

Sorry I can't be of more help than this.

 

[Zorast]

@Zorast - the latest BetterDisplay "internal pre-release" version (to get it, enable both `Receive pre-release updates` and `Receive internal pre-release updates` under Settings > Application > Updates) should have an improved configuration protection for this unexposed refresh rate trick. Let me know if this does not work as expected.

UPDATE: This still does not work as expected (as I am now testing it on a M1 Pro with 4K@120Hz display). Will tweak it further.

Thanks ! Yes can confirm, on my side it does also not work with this pre release build.