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 !

[thewanted]

Hi all,

I could really use some help. I tried the Cable Matters USB-C --> HDMI adapter (VMM6100) + AmazonBasics HDMI 2.1 cable, and could not get it to run at 4K120 on my LG 42" C2, even after flashing the firmware. It would only run at 4K30.

I've received the Anker 518 USB-C --> HDMI adapter today, along with an Anker HDMI 2.1 (certified) cable, and it will now only run at 4K60 max.

What am I doing wrong?

Ignore the above. I now have 4K120 working after flashing the VMM7100 firmware in the OP.

How can I switch between YCBCr and RGB modes? My C2 is running in RGB but I want to compare text in YCBCr mode.

 

[djlythium]

Okay, my turn! 😅

• M1 MacBook Pro
• Cable Matters 48Gbps HDMI Video Adapter (201428), which CM says should work for all of this because it's VMM7100.
• Parallels + Windows 11 (all up to date)

The adapter does not show up in Preferences > Devices. Not even my monitor show up. BUT connecting the adapter + an HDMI 2.1 cable (tried a couple, Including one I KNOW runs 4K 120hz) to the Mac makes my LG C2 work just fine.

@AironMan @NGHTCRWLR @davidawolf @eltron Any ideas? What am I missing?

TYIA!

 

[mcflury]

Surprisingly, this seems to work perfectly with an "ezcoo" HDMI 2.1 KVM switch thrown into the mix. I got the 4 port model, not really expecting it to operate at 4k120hz+HDR (given the warnings about finicky cables and this being some Ali-expresque brand), but it worked right away, with 3ft Amazon Basics "48Gbps" cables.

M1 MacBook Pro 14 -> VMM7100 -amzn hdmi-> ezcoo KVM -amzn hdmi-> LG C2 42" M1 MacBook Max 16 -> VMM7100 -amzn hdmi->
It even works with a couple Thunderbolt 3 docks. The CalDigit TS3 was limited to 60hz, but an intpw TB3 dock somehow runs at 4k120hz with HDR.

Hope this helps someone out there.

 

[thewanted]

EDIT: Removed.

 

[Random_Matt]

Would a USB-C to Displayport enable 4K/60 FPS/10 Bit? A dell monitor I may pick up is only HDMI 2.0.

 

[djlythium]

View attachment 2219511 Okay, my turn! 😅

• M1 MacBook Pro
• Cable Matters 48Gbps HDMI Video Adapter (201428), which CM says should work for all of this because it's VMM7100.
• Parallels + Windows 11 (all up to date)

The adapter does not show up in Preferences > Devices. Not even my monitor show up. BUT connecting the adapter + an HDMI 2.1 cable (tried a couple, Including one I KNOW runs 4K 120hz) to the Mac makes my LG C2 work just fine.

TYIA!

@AironMan @NGHTCRWLR @davidawolf @eltron Any ideas? What am I missing?

 

[djrobx]

Has anyone solved the wake issues with the VMM7100?

Mine works perfectly during use, but if I power off my LG C2s, both of them will power up to "No signal". I have to unplug and replug the USB C cables to get them to turn back on. I've tried changing the BetterDisplay settings and they don't seem to make a difference. I'm on Ventura 13.4.

I've set my TVs to not power off for now (screenOff instead of off)

 

[leoyzen]

I can confirm vm7100(dp2hdmi) 4k@160hz 10bit hdr working at Sonoma after flashing the firmware(not working w/o flashing) for my hackintosh(amd 6800xt) setup. And 4k@120hz 8bit at Ventura.

 

[thewanted]

Has anyone solved the wake issues with the VMM7100?

Mine works perfectly during use, but if I power off my LG C2s, both of them will power up to "No signal". I have to unplug and replug the USB C cables to get them to turn back on. I've tried changing the BetterDisplay settings and they don't seem to make a difference. I'm on Ventura 13.4.

I've set my TVs to not power off for now (screenOff instead of off)

I'm having the same problem with the Anker 518 (VMM7100) plugged into the OWC dock from the OP.

In order to get the C2 to display an image after waking the MBP up, I have to re-plug the dock into the MBP. I've also had to change the refresh rate from 60Hz to 120Hz once, but I've only had the adapter and dock for a day.

 

[sevenarth]

At a loss, need assistance from someone who understands this better than me

• MacBook Pro M1 Max
• Dell G3223Q 4k 144hz monitor
• CableMatters 201388-GRY
• AmazonBasics HDMI 2.1 cable (48Gbps)

Flashed the CableMatters adapter to latest firmware provided by CableMatters support themselves (also tried the firmware on this forum after). Plugged in to MacBook, made the relevant edits to the EDID and applied. I now have the option to select 120hz and 144hz in BetterDisplay which I didn't before, but when clicking these refresh rates, the monitor says there is no HDMI signal. The only option that gets the signal back is putting it back to 60hz. Seems like these adapters are quite hit or miss? No guaranteed way to get the VM7100 chip model so working with what I've got.

+1 to this. I have had the same exact experience. Ordered the CableMatters adapter from Amazon UK and they posted me the older one, which works great with my LG C1 but unfortunately I get the same exact result as Rosay on the Dell G3223Q.

I contacted CableMatters to see if I could get the VMM7100 – as the Anker adapter is almost twice the price here (!) – and they told me that I could get the version with the USB-C PD passthrough and sent me dedicated custom firmware for it. Ordered and will try it out tomorrow, so maybe I could give an answer to those people who wanted/will want this version instead.

 

[spinedoc77]

At a loss, need assistance from someone who understands this better than me

• MacBook Pro M1 Max
• Dell G3223Q 4k 144hz monitor
• CableMatters 201388-GRY
• AmazonBasics HDMI 2.1 cable (48Gbps)

Flashed the CableMatters adapter to latest firmware provided by CableMatters support themselves (also tried the firmware on this forum after). Plugged in to MacBook, made the relevant edits to the EDID and applied. I now have the option to select 120hz and 144hz in BetterDisplay which I didn't before, but when clicking these refresh rates, the monitor says there is no HDMI signal. The only option that gets the signal back is putting it back to 60hz. Seems like these adapters are quite hit or miss? No guaranteed way to get the VM7100 chip model so working with what I've got.

Seems like this entire solution is quite hit or miss, maybe there are differences between same model number adapters. I know I can't get the VMM7100 to work at all at 120hz on a LG CX. I'm tempted to swap it out through Amazon and see if a different unit might work.

 

[Activity3565]

Got the firmware update for the DP -> HDMI adapter working but cant get any input of out my Steam Deck dock. The screen shows up for a split second when i first plugin the doc to my 2020 M1 Air, but then goes to "No Signal" on my LG C1.Tried multiple HDMI 2.1 certified cables but no luck at 120hz.

 

[djrobx]

Seems like this entire solution is quite hit or miss, maybe there are differences between same model number adapters. I know I can't get the VMM7100 to work at all at 120hz on a LG CX. I'm tempted to swap it out through Amazon and see if a different unit might work.

Are you enabling HDMI Deep Color?

On my 7100 with my LG C2, if that setting is off, I only get 4k@30hz. It jumps to 120hz when I turn that on.

 

[sevenarth]

Great news from my end!

I have managed to get 4K@120Hz RGB 10bit and HDR on both my LG C1 and Dell G3223Q with just a firmware update – as expected from VMM7100!

I have used the CableMatters 201428-GRY adapter (HDMI 2.1 + USB-C PD 100W) which has the VMM7100 chip, and was said that it doesn't work. Well turns out it works... but with its own firmware which I am attaching and sadly flashing only on a Windows PC, so the Parallels trick doesn't work – @djlythium @AironMan

 

[spinedoc77]

Are you enabling HDMI Deep Color?

On my 7100 with my LG C2, if that setting is off, I only get 4k@30hz. It jumps to 120hz when I turn that on.

Yes I have deep color enabled, I still get 4k@60hz, just not 120hz and only 8bpc. I'm baffled as to why it won't work, I'm going to swap it out and see if the hardware makes a difference.

 

[austinmrs]

Anyone has an issue where some vertical lines appear on the screen? Normally just 1 vertical line. It's very noticeable watching videos or if you grab and move a window around. Turning the monitor on and off fixes it.

Only happens when using the flashed adapter. Using the anker one.

 

[djlythium]

Great news from my end!

I have managed to get 4K@120Hz RGB 10bit and HDR on both my LG C1 and Dell G3223Q with just a firmware update – as expected from VMM7100!

I have used the CableMatters 201428-GRY adapter (HDMI 2.1 + USB-C PD 100W) which has the VMM7100 chip, and was said that it doesn't work. Well turns out it works... but with its own firmware which I am attaching and sadly flashing only on a Windows PC, so the Parallels trick doesn't work – @djlythium @AironMan

Glad that adapter works! It’d be a great single-plug solution for me. I could never get Parallels to work, and I don’t have access to a PC with usb-c DP alt mode. BUT Cablematters offered to flash the adapter for me! 👏🏼👏🏼👏🏼 I sent it to them, they’ll flash it, then send it back, and it should be GtG. 🤞🏼

 

[bananataffy]

If you're not connected to a display, the flashing software simply won't launch, it won't be able to find the chip. You don't have to connect to a 120Hz TV, just any external HDMI display. It doesn't matter if it's OLED or TFT, 60Hz or 120Hz, HDR or SDR, as long as it can display HDMI, you should be good. But you won't be able to confirm the 10-bit HDR 120Hz without having access to such a device.

That's what I figured, thanks.

Just wanna update that I've been using the flashed Anker adapter for the past week with my M1 Mac Studio and Windows PC, connected to my 42" LG C2. 4K/120Hz/10bit...everything's been perfect so far. I switch inputs between my Mac and PC many times throughout the day and haven't had a single issue thus far (knock on wood.)

 

[djrobx]

If you're not connected to a display, the flashing software simply won't launch, it won't be able to find the chip. You don't have to connect to a 120Hz TV, just any external HDMI display. It doesn't matter if it's OLED or TFT, 60Hz or 120Hz, HDR or SDR, as long as it can display HDMI, you should be good. But you won't be able to confirm the 10-bit HDR 120Hz without having access to such a device.

For clarity, this is only true when using VMMDPTool. If you use VMMHIDTool from the Microsoft store, it will find the board as long as it is connected to the USB port, regardless if there is a display attached or not.

 

[Jashi]

I can confirm vm7100(dp2hdmi) 4k@160hz 10bit hdr working at Sonoma after flashing the firmware(not working w/o flashing) for my hackintosh(amd 6800xt) setup. And 4k@120hz 8bit at Ventura.

is it 4:4:4?

 

[leoyzen]

@Jashi Yes. Displayport DSC has been fixed in Sonoma for both AMD Graphics and Apple silicon chips.

is it 4:4:4?

 

[spinedoc77]

I can definitely confirm this doesn't work on a M2 Mac Mini 8gb. I tried it on 2 different VM7100's and no go, max 4k/60hz/8bpc.

 

[thewanted]

I can definitely confirm this doesn't work on a M2 Mac Mini 8gb. I tried it on 2 different VM7100's and no go, max 4k/60hz/8bpc.

Did you flash the VMM7100 with the custom firmware? My Anker one wasn’t “plug and play” as the OP suggests.

 

[spinedoc77]

Did you flash the VMM7100 with the custom firmware? My Anker one wasn’t “plug and play” as the OP suggests.

Yep, tested with 2 different VMM7100's. Verified in the firmware app that the correct firmware was applied.

 

[tman2damax]

Has anyone gotten a direct USB-C to HDMI cable working? I have a Belkin cable and was pleased to see it was detected as VMM7100. I have an M2 Air running parallels and trying to flash the .112 firmware just seemed to 'fry' my cablem it's still detected as connected, but absolutely no display. Tried on multiple different macs and a windows computer and the cable just seems dead now. Would a custom firmware need to be written for it to work properly? This is the FW info I get out of it after flashing the updated firmware: