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 !

[waydabber]

Complete success. Thanks @AironMan for the step-by-step instructions and the firmware update for the 201388-GRY!

One annoyance though is that Config Protection does not seem to properly protect HDR status and I have to re-enable that after every sleep. I'll fix that in an update as it can't stay like this!

Note: I use a Philips 9506 mini-LED TV, but it seems to behave the same way as the LG C2 in this regard.

 

[waydabber]

Here is a build with a minor change that enforces HDR protection better:

https://github.com/waydabber/BetterDisplay/releases/download/v1.4.7/BetterDisplay-v1.4.7b.dmg

 

[Haworthie]

Here is a build with a minor change that enforces HDR protection better:

https://github.com/waydabber/BetterDisplay/releases/download/v1.4.7/BetterDisplay-v1.4.7b.dmg

Awesome, thanks for the new build!
HDR not sticking has been an ocassional issue.
A much bigger problem for me though is that after every sleep the internal display starts mirroring the tv.
And after disabling the mirroring the display arrangement needs to be changed.
Could you please add protection for the mirroring and arrangement state?
I'd really appreciate it, thanks!

 

[waydabber]

Awesome, thanks for the new build!
HDR not sticking has been an ocassional issue.
A much bigger problem for me though is that after every sleep the internal display starts mirroring the tv.
And after disabling the mirroring the display arrangement needs to be changed.
Could you please add protection for the mirroring and arrangement state?
I'd really appreciate it, thanks!

Hmm. Now that's something probably totally unrelated issue. Try resetting the windowserver configuration, probably there is a layout/arrangement that gets activated however briefly that has the mirroring set up and that sticks somehow.

 

[dinvlad]

Hi folks - sorry for a newbie question: in this setup, the TB4 connection can only be used for video signal and nothing (or not much) else, correct? More specifically, I wanted to confirm there's not enough bandwidth to also pass a 10GbE network connection over the same cable while using the display in 4k@120Hz 4:4:4 10b HDR?

 

[tippyvtop]

Made an account for this.

Unfortunately I can't 4K 120Hz to work for my case.

I purchased a 1.5 Moshou USB-C to HDMI cable (both male), with M1 pro MBP and LG C2. I believe I flashed the firmware correctly (6.03.002) and it's the correct chip (VMM6100).

I exported and uploaded the custom EDID binary in BetterDisplay however after it is applied there's been a range of issues e.g. no signal to TV, TV reporting 'invalid format'... Tried doing it multiple times however no success.

Attached is the original and modified EDID files, and a screenshot of my display information. Tried OP's EDID also but no success either.

I'm not sure what I am doing wrong, if anyone could help I would greatly appreciate it!

Update: After much back and forth, I somehow got it to work!! (4K 120Hz 10b). Not perfect as there are some stability issues with white flashes and loss of signal. Not sure what was the issue at heart, but I uninstalled BD, and used OP's bin file instead of modifying my own EDID with AW EDID editor.

Thanks for the contributions, I have purchased BD Pro to show my support. If anyone could discover what I did wrong above please let me know

 

[shinseiryu]

Ordered the 201388-GRY from Amazon on 3/26/2023 at: https://www.amazon.com/dp/B08MSWMXT4?psc=1&ref=ppx_yo2ov_dt_b_product_details

Received it today and it is VMM6100. It was packaged in a clear plastic bag with no branding.

Had to restart my laptop before the cable matters app would load in windows 11. Downloaded existing firmware and flashed modified firmware without issues.

Originally the EDID update would not take but I was modifying it while my res was at HiDPI 3360x1890. Changed to 4k res and downloaded EDID and modified and it worked.

 

[Setuna3450]

First of all: you CAN flash the cable with a Mac!
As mentioned by @Skowt (#291) Synaptics has a different tool for flashing "VmmHIDTool". It is available in MS Store: https://apps.microsoft.com/store/detail/vmmhidtool/9PDS6MLXXS7S and requires no MS account login to download. This tool can be used on a VM via Parallels with a standard Win11 install using the wizard in Parallels:

View attachment 2180024

You simply need to make sure the USB portion of the adapter is passed to the VM. If it doesn't work immediately unplug the USB part of the cable and reconnect it. Then pick to connect to Windows directly.

View attachment 2180025


----------

I'm testing the cable version of the adapter with VMM7100 (https://www.amazon.com/dp/B08QDV5H4M).

I tried flashing the 7.02.130 as well as the firmware posted by @AironMan (#298). One unique thing I saw was that the firmware from AironMan flashes MUCH faster than the .130 and it reports as 7.02.102. However, despite that I don't see good progress:

7.02.130 (same with and w/o EDID hack)
- No RGB mode
- 4K@120 420, no HDR available
- 4K@60 422, HDR available

7.02.102 (same with and w/o EDID hack)
- No RGB mode
- 4K@120 - no signal, no HDR available
- 4K@60 w/o HDR works at 444; with HDR only at 422


(while modifying EDID I used my own, not a pre-made one; I'm using MBP w/M1 Max and LG C2 w/newest webOS)

----------

I played with the "Debug" tab in the Synaptic's tool and it has a very nice function - Dump All registers. On firmware .130 it shows more information than just "FW VERSION" button:
- SST 4 lanes HBR3
- DSC enabled on the DP side
- "DSC decompression enabled" -> suggesting that the chip is stripping DSC when needed, i.e. the lack of reported DSC on the display has nothing to do with Mac using DSC or not
- "3840x2160@119.99Hz YUV444 8bpc" for RX (i.e. DP) suggesting that Mac is using 444
- On the TX (HDMI) side thou: "HDMI2.1 FRL 3Lane 6GHz" ... "3840x2160@119.99Hz YUV420 8bpc" suggesting that negotiation on HDMI fails to reach 444... crappy cable from CM? Sometimes I see "digital snow" or green screen when connected.

Hi,
Newly registered to chime in here. I guess in your case, you’re using the dongle right? I used Mushou USBC to HDMI cable and Parallel can’t seem to recognise the usb chipset, hence VmmTool couldn’t be opened. Is there any workaround you reckon?

 

[waydabber]

Made an account for this.

Unfortunately I can't 4K 120Hz to work for my case.

I purchased a 1.5 Moshou USB-C to HDMI cable (both male), with M1 pro MBP and LG C2. I believe I flashed the firmware correctly (6.03.002) and it's the correct chip (VMM6100).

View attachment 2181462

I exported and uploaded the custom EDID binary in BetterDisplay however after it is applied there's been a range of issues e.g. no signal to TV, TV reporting 'invalid format'... Tried doing it multiple times however no success.

Attached is the original and modified EDID files, and a screenshot of my display information. Tried OP's EDID also but no success either.

I'm not sure what I am doing wrong, if anyone could help I would greatly appreciate it!

Update: After much back and forth, I somehow got it to work!! (4K 120Hz 10b). Not perfect as there are some stability issues with white flashes and loss of signal. Not sure what was the issue at heart, but I uninstalled BD, and used OP's bin file instead of modifying my own EDID with AW EDID editor.

Thanks for the contributions, I have purchased BD Pro to show my support. If anyone could discover what I did wrong above please let me know

It is probably the cable. I had to try a bunch of HDMI cables until it worked properly with one. Some worked at 60Hz only, an other had intermittent signal losses, some of them seemed to work at 100Hz but not reliably at 120Hz - so you really need a top-notch cable for things to work reliably.

 

[Zorast]

This Brand has 100% Certified cable:

KabelDirekt – 8K/4K HDMI-2.1-Kabel – 1,5 m – von HDMI zertifiziert für höchste Qualität (8K@60Hz, Ultra High Speed/48G, neuester Standard, optimal für PS5/Xbox, Monitor/TV/Beamer, silbern)

KabelDirekt – 1,5 m – 8K HDMI 2.1 Ultra High Speed HDMI Kabel, zertifiziert (48G, 8K@60 Hz, neuester Standard, offiziell lizenziert/getestet für perfekte Qualität, optimal für PS5/Xbox, silber/sch...

www.amazon.de

or (to expensive)

Ultra HDTV 8K HDMI-Kabel - 1,5m Ultra High Speed HDMI 2.1 Kabel, 48 Gbps für 8K@60Hz & 4K@120Hz - Premium Zertifikat - DTS: X, HDCP 2.2&2.3, HDR10+, eARC

Unser 8K HDMI 2.1 Kabel bietet ultimative Leistung und Kompatibilität mit allen 8K- und 4K-fähigen Geräten. Mit einer Bandbreite von 48Gbps ermöglicht es eine erstklassige Video- und Audioqualität...

www.amazon.de

I liked that to the OP.

Probably I will remove the MOSHU Adapters with long HDMI Cable from OP. But for some Guys it works perfect with them.

 

[tippyvtop]

It is probably the cable. I had to try a bunch of HDMI cables until it worked properly with one. Some worked at 60Hz only, an other had intermittent signal losses, some of them seemed to work at 100Hz but not reliably at 120Hz - so you really need a top-notch cable for things to work reliably.

Yeah the reliability improved when dropped from 120 to 100Hz, still not great though with multiple blank screens per hour. To be honest given the instability I will probably drop back down to 60Hz.

@AironMan it might be due to the cable, but I had issues with uploading EDID successfully. So it could be my user error also. At this stage I can't place my finger on what the culprit is.

I'll purchase a new HDMI cable soon, as I also received a CM adapter with VMM6100 module today. That wasn't working either (could only get 4K 30Hz) but I used a cheap cable. I'll give updates if I get success.

Feel free to provide any suggestions, willing to give it a go over the weekend!

 

[kiler129]

Hi,
Newly registered to chime in here. I guess in your case, you’re using the dongle right? I used Mushou USBC to HDMI cable and Parallel can’t seem to recognise the usb chipset, hence VmmTool couldn’t be opened. Is there any workaround you reckon?

I'm not sure about Mushou cable but it should work the same way. Can you post a screenshot from the macOS system information? They all should have USB potion, sometimes named differently.
The USB connection is finicky at times and requires reconnecting the cable if it doesn't work. You have to use the HID version of Vmm as well.

It is probably the cable. I had to try a bunch of HDMI cables until it worked properly with one. Some worked at 60Hz only, an other had intermittent signal losses, some of them seemed to work at 100Hz but not reliably at 120Hz - so you really need a top-notch cable for things to work reliably.

Seconding that. I checked a box of cables I have and only 2 worked correctly.

 

[mrcobra92]

Is there a standard displayport to HDMI adapter or cable that uses the VMM6100 that can support this trick? I am currently using the cablematters USBC to HDMI 2.1 adapter with the VMM6100 that works great, but it would be nice to use the displayport 1.4 out on my dock rather than take up one of the USB C/thunderbolt ports on it.

 

[kiler129]

Is there a standard displayport to HDMI adapter or cable that uses the VMM6100 that can support this trick?

Not tested but https://www.amazon.com/gp/product/B08XFSLWQF/ (CableMatters DisplayPort to 8K HDMI Adapter (102101)) should have VMM6100.

 

[Phil108]

How does this work for everyone when putting the Mac to sleep?

Using the VMM7100 and getting 4k 120hz 444 8b.

Every time I put my MBP 16" M1 Max to sleep the adapter won't recognize it and keeps displaying a black screen on my LG C2 and when I wake the MBP up again I have to replug the CM adapter first.

Not sure if it'll be worth the trouble if I have to unplug it each time I start working on my desk.

 

[Zorast]

Is there a standard displayport to HDMI adapter or cable that uses the VMM6100 that can support this trick? I am currently using the cablematters USBC to HDMI 2.1 adapter with the VMM6100 that works great, but it would be nice to use the displayport 1.4 out on my dock rather than take up one of the USB C/thunderbolt ports on it.

Plz order one, test and report

 

[waydabber]

How does this work for everyone when putting the Mac to sleep?

Using the VMM7100 and getting 4k 120hz 444 8b.

Every time I put my MBP 16" M1 Max to sleep the adapter won't recognize it and keeps displaying a black screen on my LG C2 and when I wake the MBP up again I have to replug the CM adapter first.

Not sure if it'll be worth the trouble if I have to unplug it each time I start working on my desk.

I am not sure about the VMM7100. With the VMM6100 sleeps seem to work fine.

 

[kiler129]

I tested another cable: https://www.amazon.com/dp/B0BK7TWQ2G (XZOND USB C to HDMI 2.1 Adapter Cable - 8K 60Hz HDR - 4K 120Hz - 1080P 240Hz - 6ft Cable - for MacBooks, PCs, iPads, Projectors, Ultrawide displays, Monitors, TVs – Thunderbolt Compatible). It is VMM6100-based but hold your horses: it's bad. It does work but only up to 4K@60 - anything higher and the picture will be dropping for 2-3s every minute. With 100Hz it sometimes works for 10-15s and then black-screens.


@Setuna3450: Also, regarding flashing: VMM7100 can be flashed using Parallels/UTM, but VMM6100 cannot as it uses USB billboard pseudo-device that isn't separable from the DP portion (as it's not a real device). This can be verified using e.g. ioreg -p IOUSB -l -w0, or simply seeing that in System Information it doesn't list neither speed nor currents required.


@AironMan: at this point it may be beneficial to probably add to OP all cables that do not work or work crappily. I know one of your post in the 47 pages thread also had some tested ones.

---

At this point I'm almost ready to ditch LG C2 for Asus PG42UQ that has DP, making 4K@120Hz with HDR and VRR natively supported as USB-C => DP cables are nearly passive (minus the chip to tell the computer to enable DP-Alt mode but no signal conversion is happening).

 

[NGHTCRWLR]

At this point I'm almost ready to ditch LG C2 for Asus PG42UQ that has DP, making 4K@120Hz with HDR and VRR natively supported as USB-C => DP cables are nearly passive (minus the chip to tell the computer to enable DP-Alt mode but no signal conversion is happening).

Well, one would hope that but I have a Mac mini M1 with a Dell G3223Q (4K/144hz). With a USB-C to DP 1.4 cable (coincidentally from Cable Matters) I have the option to utilise the display up to 144Hz at 4K, however, if I go to any frame rate higher than 60hz the Mac outputs YCbCr in either 422 or 420 (haven't been able to confirm) but either way the text looks rubbish especially when coloured or on a colour background from fuzzier edges and fringing.

So I have to stay at 4K/60 to get RGB 10bit, where text looks very nice.

Have tried EDID edits to force RGB or YCbCr 444 at the higher frame rates and so far anything I do just causes the choices for any frame rates higher than 60hz to go away completely in both Mac display settings and Better Display.

So if anybody knows how to use a Mac mini M1 with a native DisplayPort connection at 4k/120 with some kind of 444 chroma I would appreciate any help, because I am not finding that easy to do either.

 

[Zorast]

I tested another cable: https://www.amazon.com/dp/B0BK7TWQ2G (XZOND USB C to HDMI 2.1 Adapter Cable - 8K 60Hz HDR - 4K 120Hz - 1080P 240Hz - 6ft Cable - for MacBooks, PCs, iPads, Projectors, Ultrawide displays, Monitors, TVs – Thunderbolt Compatible). It is VMM6100-based but hold your horses: it's bad. It does work but only up to 4K@60 - anything higher and the picture will be dropping for 2-3s every minute. With 100Hz it sometimes works for 10-15s and then black-screens.


@Setuna3450: Also, regarding flashing: VMM7100 can be flashed using Parallels/UTM, but VMM6100 cannot as it uses USB billboard pseudo-device that isn't separable from the DP portion (as it's not a real device). This can be verified using e.g. ioreg -p IOUSB -l -w0, or simply seeing that in System Information it doesn't list neither speed nor currents required.


@AironMan: at this point it may be beneficial to probably add to OP all cables that do not work or work crappily. I know one of your post in the 47 pages thread also had some tested ones.

---

At this point I'm almost ready to ditch LG C2 for Asus PG42UQ that has DP, making 4K@120Hz with HDR and VRR natively supported as USB-C => DP cables are nearly passive (minus the chip to tell the computer to enable DP-Alt mode but no signal conversion is happening).

This is to much work. There are now 5 alternatives that work, this must be enough. The other ones have to read the thread or ask.

 

[MananTank]

Working! Using the cable Matters adapter. Did not even have to update the firmware. Plugged it in, fired up the Better display - followed the steps in this video -

and boom 4k@120hz on LG C2!

Note: I initially had the display cut off on the corners, but when I changed the input type to "PC" in LG C2, it got fixed.

 

[Zorast]

Working! Using the cable Matters adapter. Did not even have to update the firmware. Plugged it in, fired up the Better display - followed the steps in this video -

and boom 4k@120hz on LG C2!

Note: I initially had the display cut off on the corners, but when I changed the input type to "PC" in LG C2, it got fixed.

This is only 4:2:2 !

 

[MananTank]

This is only 4:2:2 !

How do I check that it's 4:2:2? and how do I make it 4:4:4 ?

 

[mrwuf]

Do any thunderbolt 4 docks support 4K 120 Hz to an LG C2 on M1 Pro? I need a dock anyway, so figured I'd ask. Looking at this OWC or this Kensington. (edited link)

 

[joevt]

Do any thunderbolt 4 docks support 4K 120 Hz to an LG C2 on M1 Pro? I need a dock anyway, so figured I'd ask. Looking at this OWC or this Kensington. (edited link)

A Thunderbolt dock should never limit the DisplayPort connection so it shouldn't matter.
You want a Thunderbolt 3 dock that supports DisplayPort 1.4 or a Thunderbolt 4 hub/dock.
You don't want a dock with an HDMI port, because then you'll be stuck with whatever DisplayPort to HDMI adapter is used inside the dock.