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 !

[davidawolf]

2023-03-20 Today I followed all of the instructions and applied the firmware to my Cable Matters adapter with the VMM6100 chip. See proof below. I edited and uploaded the EDID with the 'DisplayPort' setting. I rebooted my Mac Studio and when it still didn't include 120Hz options I unplugged and replugged the adapter several times. Still no 120Hz settings. See BetterDisplay resolution options below.

Any suggestions?

 

[BeatCrazy]

2023-03-20 Today I followed all of the instructions and applied the firmware to my Cable Matters adapter with the VMM6100 chip. See proof below. I edited and uploaded the EDID with the 'DisplayPort' setting. I rebooted my Mac Studio and when it still didn't include 120Hz options I unplugged and replugged the adapter several times. Still no 120Hz settings. See BetterDisplay resolution options below.

Any suggestions?
View attachment 2176386
View attachment 2176385

What display are you using?

 

[davidawolf]

What display are you using?

LG OLED C2 55"

 

[BeatCrazy]

LG OLED C2 55"

Which HDMI cable?

And did you "apply" the BetterDisplay EDID profile as described in step #6 of the OP?

 

[davidawolf]

Thanks for your help.

Monoprice 8K Certified Braided Ultra High Speed HDMI 2.1 Cable - 10 Feet - Black | 48Gbps​

The checkbox in BetterDisplay Version 1.4.6 Build 14593 for EDID override options - Automatically apply custom EDID upon detection of this display is checked per step #6. I'm using Mac Studio M1 Max + LG OLED C2 55" + cable matters 201388 VMM6100 with proper firmware as supplied on page 1 of this forum.

 

[davidawolf]

I redid all of the steps without any change. I should mention that my 60Hz is at 3840x2160. BetterDisplay offers me the below 120Hz options, but they are all lower resolution. Still not working for me.

 

[BeatCrazy]

Thanks for your help.

Monoprice 8K Certified Braided Ultra High Speed HDMI 2.1 Cable - 10 Feet - Black | 48Gbps​

The checkbox in BetterDisplay Version 1.4.6 Build 14593 for EDID override options - Automatically apply custom EDID upon detection of this display is checked per step #6. I'm using Mac Studio M1 Max + LG OLED C2 55" + cable matters 201388 VMM6100 with proper firmware as supplied on page 1 of this forum.

A few more things:

• Do you have another cable you can test with?
• Do you have another M1 Mac you try with?
• Are you running through an AVR, or directly to the C2?

 

[davidawolf]

A few more things:

• Do you have another cable you can test with?
• Do you have another M1 Mac you try with?
• Are you running through an AVR, or directly to the C2?

I only have two HDMI 2.1 cables and they are the same brand and cable. I do not have another Mac. The video route is:
Mac Studio M1 Max ==> Thunderbolt 4 port ==> Cable Matters 201388-GRY VMM6100 adapter with the 'proper' firmware confirmed ==> Monoprice 8K Certified Ultra High Speed HDMI 2.1 Cable 48Gbps ==> HDMI 4 port ==> LG OLED C2 55" tv. NO AVR.

I used the same HDMI 2.1 cable on a Windows 11 with thunderbolt USB-C port to burn the firmware onto the VMM6100.

 

[BeatCrazy]

I only have two HDMI 2.1 cables and they are the same brand and cable. I do not have another Mac. The video route is:
Mac Studio M1 Max ==> Thunderbolt 4 port ==> Cable Matters 201388-GRY VMM6100 adapter with the 'proper' firmware confirmed ==> Monoprice 8K Certified Ultra High Speed HDMI 2.1 Cable 48Gbps ==> HDMI 4 port ==> LG OLED C2 55" tv. NO AVR.

I used the same HDMI 2.1 cable on a Windows 11 with thunderbolt USB-C port to burn the firmware onto the VMM6100.

Do you have a GPU on your Windows PC so you can confirm you're able to display 4K/120 on your LG? Trying to rule out the TV here.

Also, you might as well rename your HDMI 4 input label to "PC". https://www.reddit.com/r/LGOLED/comments/tq8e6l

 

[davidawolf]

Do you have a GPU on your Windows PC so you can confirm you're able to display 4K/120 on your LG? Trying to rule out the TV here.

Also, you might as well rename your HDMI 4 input label to "PC". https://www.reddit.com/r/LGOLED/comments/tq8e6l

Unfortunately the Windows PC is miles away. I went there to burn the firmware. It's not mine.

I can successfully switch to HiDPI 120Hz, 8bpc 2560x1440. However, that isn't what I want for a resolution.

I have already renamed my HDMI icon to the PC icon. Thanks.

 

[BeatCrazy]

Unfortunately the Windows PC is miles away. I went there to burn the firmware. It's not mine.

I can successfully switch to HiDPI 120Hz, 8bpc 2560x1440. However, that isn't what I want for a resolution.
View attachment 2176409
I have already renamed my HDMI icon to the PC icon. Thanks.

Yeah that 2560x1440 max means you still have a problem.

At this point, the next steps you really need to take are to borrow another M1 Mac and/or Windows PC with an HDMI 2.1 GPU so you can confirm if the problem lies on the display end, or the Mac/adapter end.

 

[davidawolf]

Yeah that 2560x1440 max means you still have a problem.

At this point, the next steps you really need to take are to borrow another M1 Mac and/or Windows PC with an HDMI 2.1 GPU so you can confirm if the problem lies on the display end, or the Mac/adapter end.

On the same Mac M1 thunderbolt/usb-c output, I am connected into my Dell AW3420DW monitor with DisplayPort at 4k120Hz10bpc. So I believe that my Mac M1 video signal performs as expected. I tried a different TV port and a different HDMI 2.1 cable between the TV and the Mac. No luck.

Thank you for taking the time to help.

 

[cheeseburgerer]

On the same Mac M1 thunderbolt/usb-c output, I am connected into my Dell AW3420DW monitor with DisplayPort at 4k120Hz10bpc. So I believe that my Mac M1 video signal performs as expected. I tried a different TV port and a different HDMI 2.1 cable between the TV and the Mac. No luck.
View attachment 2176418

Thank you for taking the time to help.

Have you tried the EDID file uploaded by OP? The modified EDID doesn't work on my TCL TV either, but OP's EDID do the magic for me.
Maybe there's more to the settings than just changing the port to DP1.4.

 

[davidawolf]

Have you tried the EDID file uploaded by OP? The modified EDID doesn't work on my TCL TV either, but OP's EDID do the magic for me.
Maybe there's more to the settings than just changing the port to DP1.4.

Wow! I used the EDID in the instructions rather than using my own edits. Now I am at 3840x2160 120Hz, 8bpc. Not sure why others have 10 bpc, but THANK YOU!!!

(from BetterDisplay)

(from the Mac Display Data)

 

[davidawolf]

More info on my setup experience. Above I was setting up the Cable Matters 201388-GRY with the VMM6100 chip. The best I could do was HiDPI 120Hz, 8bpc at 3840x2160. With this adapter, I have HDR.

Since then I was able to get the Cable Matters 201388-A with the VMM7100 chip to produce HiDPI 120Hz, 10bpc at 3840x2160. I applied the firmware that @AironMan shared previously for the VMM7100. And I used his EDID file as well. With this adapter, I do not have HDR.

 

[Zorast]

The 8b showing in BD are not correct. It is 10b. u can test this when pressing many 3-4 times fast the Green Button on LG Remote.

 

[joevt]

The 8b showing in BD are not correct. It is 10b. u can test this when pressing many 3-4 times fast the Green Button on LG Remote.

Could it be 8bpc framebuffer being output as 10bpc HDMI? I think the Graphics/Displays tab in System Information.app will show framebuffer info. SwitchResX will show output timing. AllRez will show output bpc for Intel Macs that are using modern GPU drivers. Older GPUs on Intel Macs require a kext to get output bpc (my Lilu/WhateverGreen for example - though I want to try to make a kext that doesn't require Lilu/WhateverGreen). It's good to have a display that shows timing and color info.

If BetterDisplay.app is not showing the correct output bpc, then maybe it's a bug.
There's an example of AllRez output for a M1 Mac at https://forums.macrumors.com/threads/diy-5k-monitor-success.2253100/post-31258601
You see it has 3 displays. There's 4 methods to get bpc for the current display mode.
CGDisplayCurrentMode always seems to report 8bpc so it should be ignored if the other methods are available.
One of the displays shows 64bpp 16bpc but it also shows encoding --------RRRRRRRRGGGGGGGGBBBBBBBB which is 8bpc. Probably the former is true.

 

[Zorast]

Could it be 8bpc framebuffer being output as 10bpc HDMI? I think the Graphics/Displays tab in System Information.app will show framebuffer info. SwitchResX will show output timing. AllRez will show output bpc for Intel Macs that are using modern GPU drivers. Older GPUs on Intel Macs require a kext to get output bpc (my Lilu/WhateverGreen for example - though I want to try to make a kext that doesn't require Lilu/WhateverGreen). It's good to have a display that shows timing and color info.

If BetterDisplay.app is not showing the correct output bpc, then maybe it's a bug.
There's an example of AllRez output for a M1 Mac at https://forums.macrumors.com/threads/diy-5k-monitor-success.2253100/post-31258601
You see it has 3 displays. There's 4 methods to get bpc for the current display mode.
CGDisplayCurrentMode always seems to report 8bpc so it should be ignored if the other methods are available.
One of the displays shows 64bpp 16bpc but it also shows encoding --------RRRRRRRRGGGGGGGGBBBBBBBB which is 8bpc. Probably the former is true.

This is also present on my Pro Display XDR showing in SRX and BD 8b. On my LG C2 OLED some time it shows 10b but most of time 8b. I dont know what this issue in Display Color Depth is. I also ask some time ago @stevemr123 but he says that this information comes from MacOS. But it is 100% 10b because a lot of people, like me, test some patters and can confirm it's 10b. I report this also to apple, but nothing happened. But ure informations are very interesting.

 

[waydabber]

Hi guys, BetterDisplay will show 10bpc if `samplesPerPixel` is 10 - for all other occurrences (even though the reported value is sometimes 16) the app will show 8bpc as I believe the latter result (16) is not real and I did not want to confuse anybody by showing 16bpc - but I did not investigate this further. The 8 vs 10 is solely about the framebuffer - the connection might as be as well 10bits especially as the dongle can do whatever it wants, the app won't take that into account. If the framebuffer depth is 8bpc then the TV showing 10bits is irrelevant, will not make the image any better.

(+ note: I think it is really difficult to discern the difference between 8 and 10 bits in any real life setting + I never saw anything else other than 8bit on my mini-LED 4K display@120Hz with direct displayPort or USB-C connection either - 10 bits shows up on my QHD test displays usually - so I'd be surprised if this would be any different for the LG TVs)

 

[Zorast]

Hi guys, BetterDisplay will show 10bpc if `samplesPerPixel` is 10 - for all other occurrences (even though the reported value is sometimes 16) the app will show 8bpc as I believe the latter result (16) is not real and I did not want to confuse anybody by showing 16bpc - but I did not investigate this further. The 8 vs 10 is solely about the framebuffer - the connection might as be as well 10bits especially as the dongle can do whatever it wants, the app won't take that into account. If the framebuffer depth is 8bpc then the TV showing 10bits is irrelevant, will not make the image any better.

(+ note: I think it is really difficult to discern the difference between 8 and 10 bits in any real life setting + I never saw anything else other than 8bit on my mini-LED 4K display@120Hz with direct displayPort or USB-C connection either - 10 bits shows up on my QHD test displays usually - so I'd be surprised if this would be any different for the LG TVs)

Yeah but the TV does not always show 10b. So if we can not reach 10b it almost show me 8b. Like i say my Pro Display XDR also shows me 8b. And there are some scenarios where i see 10b. And this scenarios it is like @joevt say, when using 2-3 Monitors, some time it shows me 10b when Macbook 16 M1 MAX Lid is open. Or some times it shows me 10b also when only 1 Display is connected.

 

[Zorast]

We have to disable 8bit per EDID :-D

 

[Zorast]

Look here! Lid is closed but it's showing me 10b ! EDID is not touched...

 

[ASZ20]

I have the CM 7100 adapter and got 4K120 8 bit 444 (not RGB) working on my M1 Pro MacBook thanks to the custom firmware posted. I assume this is the best I can get until CM publishes a new firmware, hopefully full RGB? And is there any way to get the 444 to stick without switching between 60 and 120 when the adapter's been unplugged?

 

[m0dest]

I got this working on 2 adapters from AliExpress that have not been mentioned yet:

1. Moshou C-006 USB-C to HDMI 8K 60Hz (similar to the one mentioned before, but this is a male-to-male cable)
2. an unbranded but visually identical cable

Both of these have VMM6100. I successfully flashed them with the firmware from this thread.

I'm using them with a Samsung QN90B TV ("Neo QLED 4K") with a modified EDID that I made and applied through BetterDisplay.

With this combination, I'm able to achieve 3840x2160 @ 120 Hz 4:4:4 HDR on an M1 Max MBP. (BetterDisplay reports 8 bpc, but I know from tests that it's 10 bpc.)

Thanks!

 

[Zorast]

Looks like the Moshou is the cheapest pick till now. I update the Post with Ali Express link.