Mac mini: 4k @ 120hz?

[Flow91]

Hi,

I'm thinking about buying an LG OLED tv (CX or C9) that runs on 4k and 120 hz. I'd also like to hook up a MacOS system, but until now they wouldn't be able to make use of the display's possibilities. Now as the M1 Mac mini has been presented I wonder if it runs 4k at 120 hz smoothly.

I know that the Mac only supports HDMI 2.0, but there are adapters for transforming DisplayPort 1.4 to HDMI 2.1. What do you think, will it run? Or would an older Intel Mac with an eGPU a better solution?

Have you made good experiences with adapters for transforming DisplayPort to HDMI 2.1 signals?

 

[Djlild7hina]

Roger that. Lots of info, names and variables thrown around here 😂

Yes 😂

I'll try to consolidate the instructions since they're dug in different pages now

So basically things you'll need for 4k120 RGB 10bit

1. Cable Matters Adapter with VMM6100 (Should have VMM6100, if not you may need to order another one)
2. HDMI 2.1 Certified cable
3. Windows PC with USB-C DP capabilities. Using Parallels will not work but using bootcamp on an Intel mac should.
4. Cable Matters update tool to upgrade/downgrade firmware
5. BetterDisplay to extract/apply Custom EDID.
6. AW EDID Editor to modify EDID

Steps

1. Update the HDMI type to "PC" on your LG OLED to whichever port you are going to use. Also enable HDMI Ultra HD Color mode
2. Plug in cable matters adapter to a USB C port that supports DP on your Windows PC. The HDMI cable connected to the adapter will need to be connected to a tv/monitor for the next step.
3. Launch update tool and verify you have VMM6100. If you do not have VMM6100, you'll need another adapter. Follow steps on the Cable matters firmware page linked above but use the firmware "VMM61004k120hzRGB-Fullrom.zip" (extract first) located in this post instead.
   1. (Optional) - Make backup of your firmware first or you can restore the latest one from the update tool page.
4. Once it's completed flashing, unplug and replug the adapter to verify your new firmware version.
5. Plug the adapter back in your mac and follow the steps here to apply Custom EDID.
6. Profit!

Credits

• @AironMan - Testing numerous adapters/docks
• @stevemr123 - BetterDisplay with override EDID functionality
• @joevt - in-depth knowledge USB C protocols, firmware, and devices
• @Alan Spiegel - Reported RGB 10bit working and provided initial EDID info
• @hPandaa1 - uploaded Cable matters firmware where RGB 10bit works

Sorry if I missed someone or information so please feel to correct and I'll update this post.

Think I'll consolidate the information with more screenshots on my github here

 

[Artagra]

So, talking to some Mac System Admins, they recommend we all file similar feedback and reference to each other, as a way of getting it on Apple's radar.

So anyone who would actually use this and cares about this issue, consider submitting a "feedback" via Feedback Assistant or the web portal, and reference my feedback - FB9734589. Then, post your feedback number here.

In order to do so, you will probably need to be enrolled in the Beta program (but don't need to be running the Beta OS). I have confirmed this problem applies on the current Monterey Beta.

Here's a link with how to file feedback:

https://www.imore.com/how-submit-feedback-betas

I feel like this could be such a tiny thing for Apple to fix if it is just the clock issue, and would really remove any complaints around the HDMI port only being 2.0

 

[joevt]

Just read the specs.

“One display with up to 6K resolution at 60Hz connected via Thunderbolt and one display with up to 4K resolution at 60Hz connected via HDMI 2.0.”

120 Hz > 60 Hz. So, no.

Refresh rate is not a limiter for GPUs. Pixel clock is.

HDMI 2.0 is limited to 600 MHz pixel clock (8 bpc). HDMI 2.0 4K 60Hz is 594 MHz. More than 8 bpc requires chroma sub sampling.

Normally, DisplayPort 1.4 is limited to 864 MHz for 10bpc and 1080 MHz for 8bpc (actual numbers are less because of overhead). DSC can effectively triple that to allow 8K 60Hz (2376 MHz).

HDMI 2.1 is limited to 1422 MHz 10bpc without DSC (DSC can be used by HDMI 2.1 to triple that).

5K 60 Hz is ~933 MHz
4K 120Hz is 1188 MHz (HDMI)
6K 60Hz is 1286 MHz (uses DSC)
8K 60Hz is 2376 MHz (HDMI)
8K 120Hz is 4752 MHz (HDMI) (4258 MHz using CVT-RB2 timing)

The Club-3d DisplayPort 1.4 to HDMI 2.1 4K 120Hz adapter uses DSC.

 

[SerpentEagle]

I have also created a post on Reddit calling on others to file bug reports as well.

https://www.reddit.com/r/mac/comments/r8inmn

 

[Artagra]

I have reached out to HDfury on Discord who created the Dr HDMI 8k (reprogrammable EDID Manager) and he was kind enough to provide these values for testing, if anyone has an EDID Manager, he suggests giving this a try with a `DP -> HDMI Adapter`

the attached file is an EDID file that can be loaded into any EDID manager (From Dr HDMI, or any other)


I was hoping that the Dr HDMI 8k could be used to spoof the EDID/Timings needed to run 4k 120hz through an adaptor, but he is unsure at this point if this would be possible with his device.

I am in over my head here, but grasping at straws in attempt to help get this effort moving. I hope this is of use to someone.

Just ordered one - I looked into "HDMI Pass-Through EDID Emulators" but hadn't found one that looked promising, but this Dr HDMI 8k does.

Thanks for the info! I will try it and report back.

For anyone else interested:

Dr HDMI™ 8K | HDFury.com | Connect and Fix everything in HDMI

World First HDMI™ 2.1 EDID Manager with webserver and Android/iOS APP! Up to FRL5/40Gbps/1200MHz signal passthru with VRR support + FRL6/48Gbps/1500MHz under testing The Dr.HDMI™ 8K Kit includes: Dr.HDMI™ 8K unit Choice of power supply USB power cable (6ft)

hdfury.com

Join the HDfury.com Discord Server!

Check out the HDfury.com community on Discord - hang out with 17119 other members and enjoy free voice and text chat.

discord.com

 

[Artagra]

My report to Apple - please let me know anything I've missed or got wrong!

MacOS incorrectly limiting pixel clock to 600mhz on Display Port 1.4 to HDMI 2.1 adapters, preventing 4k120

Description of the problem: Unable to display 4k120 on an external HDMI 2.1 display via a Displayport 1.4 to HDMI 2.1 adapter. It appears that MacOS is incorrectly limiting the pixel clock to 600mhz on such adapters, preventing 4k120.

Adapters such as the Realtek RTD2173 and the Synaptics VMM6100 allow the conversion of a Display Port 1.4 signal to HDMI 2.1, allowing the support of external 4k120 displays such as the LG OLED CX and others. Mac hardware and MacOS supports output of a Displayport 1.4 signal, however when one of these adapters are plugged, MacOS appears to detect the 600mhz Display Clock (which is still communicated across the adapter, even though it is no longer applicable. The same adapter works on a 2019 Macbook Pro 16” (Intel) in Windows via Bootcamp, but does not work in MacOS.

Expected result: 4k120 output

Actual result: 4k60 output

How to reproduce: Connect an LG CX (or other HDMI 2.1 display that supports 4k120) into a Mac that supports Display Port 1.4 over USB-C via a DP1.4 to HDMI2.1 adapter - output will be limited to 4k60, and will not be 4k120.


Additional info:

- Nvidia had a very similar issue in one series of Windows drivers - https://www.nvidia.com/en-us/geforc...e-46192-game-ready-driver-feedback-thread-re/ “Realtek Displayport-to-HDMI 2.1 protocol converter clock limited to 600MHz pixel clock [3202060]”

- Multiple brands sell adapters using these chips, including Club3d and Cable Matters - https://www.cablematters.com/pc-1368-122-usb-c-to-8k-hdmi-adapter.aspx and https://www.amazon.ca/Club-3D-DisplayPort1-4-4K120Hz-CAC-1085/dp/B08BX49V5V

- Macrumors thread related to the issue: https://forums.macrumors.com/threads/mac-mini-4k-120hz.2267035/page-6

 

[waydabber]

Ok, we did some experimenting with @AironMan

We were able to activate 4K@120Hz (it's YCbCr422 though, might be improved) using a cooked EDID and using BetterDisplay's EDID override feature for Apple Silicon.

Hardware:

- M1 MAX Macbook Pro 16
- LG TV C2 42"

Screenshots:

I attached the EDID I cooked up for the C2. UPDATE: removed cooked EDID as using this might lead to confusion as identifiers might not match the display's original identifiers - it's better everyone follows the tutorial.

What I did with the EDID was to convert it to EDID v1.4 (original EDID is v1.3) and changing the video interface bits to DisplayPort.

I think this method should work with all other 4K@120Hz TVs with and compatible dongles on any M1 Macs.

 

[Zorast]

Ah, that's weird. I checked in a new browser session and it seems I can only see that post when I am logged in. Hope I didn't violate any rules of that subreddit and got shadowbanned for it...

WE GOT IT !!!

Thanks u Man, after checking ure Log and ure Firmware I was able to reproduce RGB 4k@120hz 10B after flashing Firmware (6.05.120) to an VMM6100 Cable Matters 201388 Adapter.

Its connected over 4L10 so it looks like it can use 40 Gbits to reach RGB 4k@120hz 10B!

Finally we got it ! I will report Cable Matters Support about this.

I think this solution can also been use for M2 Apple Silicon as well!

U have to override with custom EDID and change some times the frequent between 30hz-120hz. Then it will Sync with RGB 4k@120hz 10B.

Firmware is Attached and will work with Adapter Cable Matters 201388 when it has an Chip VMM6100.
(Till now we dont know if this Firmware will also work with other Brand with VMM6100!)

Can also inform that it also work when its connected to an TB4 Dock, so its also possible to get an 1 Cable solution !!

Adapter:

Cable Matters 48Gbps USB C auf HDMI 2.1 Adapter (USB C HDMI Adapter) für 4K 120Hz und 8K 60Hz HDR - Thunderbolt 3, USB4, Thunderbolt 4 Port kompatibel-Maximale Auflösung auf jedem Mac beträgt 4K 60Hz

Cable Matters 48Gbps USB-C-zu-HDMI-Adapter-Kabel unterstützt 4K 120Hz und 8K 60Hz HDR - kompatibel mit Thunderbolt-3 und Thunderbolt-4-Port - 1,8m - maximale unterstützte Auflösung auf jedem Mac 4K @ 60Hz

www.amazon.de

EDIT: Plz follow this Thread:

DP/USB-C/Thunderbolt 3/4 to HDMI 2.1 4k@120hz RGB4:4:4 10b HDR with Apple Silicon M1/M2 now possible !

WARNING 31.10.23: macOS Sonoma 14.1 and newer breaks HDR with HiDPI 4k@120hz 4:4:4 and beyond. We are looking for a solution. NOTE: To ensure proper credit for this solution, kindly reference this thread when sharing. Thanks! Apple limited HDMI-Transportstream over USB-C/TB/DP to maxed...

forums.macrumors.com

 

[waydabber]

A quick tutorial:

STEP 1. Download the display's EDID binary using BetterDisplay. Go to Settings (gear icon in the App menubar extra menu) - > Displays > Retrieve display EDID and click Retrieve EDID Data and when the EDID appears, click Export EDID Binary...

STEP 2. You need to open the exported EDID binary up in AW EDID Editor (free). This is the only simple thing you need to change in AW EDID Editor.

If this option not there, then you simply need to change the EDID format to V1.4 under Version&Revision (the Revision bit should be changed from 3 to 4).

STEP 3. You can upload the EDID Binary with the Upload EDID Binary... button and then apply the EDID here with BetterDisplay under Settings (gear icon) - > Displays > Custom display EDID. When you hit Apply EDID Now, the display should disconnect and reconnect with the new EDID in effect. You can try setting the resolution to 4K@120Hz using the app's Set Resolution menu. You can set the EDID to auto-apply as well with the right checkbox whenever the app is started at launch and the display is detected.

You can of course make all kinds of other hacks by modifying the EDID to your liking. Share your experiences!

 

[matthoffner]

I'm running M1 at 2560x1440 @ 120Hz no problem. Struggling getting 4k @ 120hz though even with the Club 3D DisplayPort to hdmi 2.1 adapter.

 

[joevt]

I contacted CableMatters about the adapter and they say it will do 4K 120 Hz with my 2080 Ti so it pretty much has to support DSC for that to happen. They claimed that it should also allow for 4K 120 Hz with Intel Macbooks, but with the adapter not being available in EU until March I cannot test it out. ARM Macbooks seem to be limited to 4K 60 Hz.

Assuming 1188MHz pixel clock,
4K 120Hz or 8K 30Hz can be done with DisplayPort 1.4 without DSC using 4:2:2 10bpc.
4K 120Hz or 8K 30Hz can be done with HDMI 2.0 using 4:2:0 8bpc (can't support HDR with 8bpc).
Your display may be able to tell you if it's using RGB or 4:4:4 and whether you are getting 8 or 10 bpc (but many displays do not - well, maybe these new HDMI 2.1 displays will want to show off their capabilities by showing you the info - to put HDMI 2.0 displays to shame).

With the CAC-1085 at least there were some very severe growing pains but with the latest firmware it works fine now on PC.

How do you get new firmware for CAC-1085? There's no download links that I could find.

Great thread, after not being wowed by the NUC 11's just release (I was hoping for HDMI 2.1) I've gone back to the mac mini m1 as the front runner. The one thing preventing me is I use a LG CX 55 as my main monitor (got used to the ABL) and would really like 4k 120 Hz.

Or is the GPU just not capable or Apple not willing to support it.

If M1 Macs have a problem with 4K 120Hz, it is probably software only since 6K 60Hz is more pixels per frame and per second.
One issue with M1 Macs is the 6K framebuffer limit so it cannot do HiDPI modes greater than 3K and it cannot do 8K 30Hz which is less pixels per second than 6K 60Hz.

I noticed this cable, is this something that would theoretically work with the Mac Mini M1
https://www.kenable.co.uk/en/usb-ca...itor-video-cable-1m-010926-5055781246531.html

That's another adapter/cable like the Club-3D or Cable Matters products. They probably all use the Realtek RTD2173.

 

[repoman27]

Whatever the case, if it is a software limitation, then it should be fixed. It has been nearly FOUR years since HDMI 2.1 was released. We cannot hold Apple to such mediocre standards.

Once again, I'm all for asking Apple to introduce support for HDMI 2.1 FRL in macOS. Just bear in mind that what you're asking is for Apple to dedicate not insignificant development resources to writing and testing a driver to support third-party hardware.

The HDMI 2.1 specification is just a document. Hardware is developed based on that spec, and then drivers can be written to support that hardware. Apple's GPUs do not support HDMI natively. They do sell AMD Navi 21 based GPUs, but the native HDMI functionality is not exposed on Apple's MPX modules. Apple is also clearly on the outs with NVIDIA, so it's unlikely they'll be releasing updated drivers for GA102 based GPUs.

That leaves DisplayPort to HDMI 2.1 protocol adapters. The dongles currently on the market use chips from either Synaptics or Realtek. While Apple does have working relationships with those companies, a functional driver generally requires input from both parties, and neither is Apple's preferred vendor for display protocol converters. Apple uses MegaChips (now part of Kinetic Technologies) for PCONs in their own hardware these days, but also have a lengthy history of working with Parade as well. Parade only launched their PS195 and PS196 DisplayPort 2.0 to HDMI 2.1 protocol converters in August, so I could easily see Apple including HDMI 2.1 FRL support in a macOS release around the same time as adapters based on those chips start showing up in the market.

 

[Zorast]

GOOD NEWS GUYS !!

Plz all u if u have an VMM7100 installed. If yes u can use this Firmware to get 4:4:4 4k@120hz 8b Without the need of editing a EDID !! Plz test and share ure results

Installer and tutorial is inside the zip !!

New CUSTOM Firmware Name is: Spyder_fw_USBC_CM_7.02.130forMac.fullrom

Hopefully a 10b solution will come next days !!
How can u test if u have an VMM7100 ?? Open the updater, it will show u the information!
U need a Windows Machine with USB C for the updater!

After flash the ROM, delete old EDID Stuff(Restore factory defaults) and reconnect the Adapter. Then change resultion from 4k@60hz to 4k@120hz 2 times, then it switched to 4:4:4 !

EDID Export of my LG 42 C2 when this Adapter is connected, u can test this EDID also on another Adapters if u want !!



EDIT: Plz follow this Thread:

DP/USB-C/Thunderbolt 3/4 to HDMI 2.1 4k@120hz RGB4:4:4 10b HDR with Apple Silicon M1/M2 now possible !

WARNING 31.10.23: macOS Sonoma 14.1 and newer breaks HDR with HiDPI 4k@120hz 4:4:4 and beyond. We are looking for a solution. NOTE: To ensure proper credit for this solution, kindly reference this thread when sharing. Thanks! Apple limited HDMI-Transportstream over USB-C/TB/DP to maxed...

forums.macrumors.com

 

[bill-p]

I have a CX so I'll let you know what happens, but I'm not expecting "smooth" 4K @ 120Hz.

Bandwidth-wise, it should be enough. Realistically, I don't think Apple is going to give support to the M1. Maybe the M1X or M2 will be able to do that.

Also, I can't fathom using the CX as a computer monitor, to be honest. Auto Brightness Limiter (ABL) is very aggressive on white screens. That and there's the risk of image retention.

 

[joevt]

Unlikely to be something we can fix ourselves because even on Windows Nvidia needed to fix their drivers for this to work. So best we can do is report it to Apple and hope their driver teams can fix it.

Some fixes made in the past just involve changing a few bytes in the drivers. Just need to find them.
https://github.com/acidanthera/WhateverGreen
https://github.com/Floris497/mac-pixel-clock-patch-V2
https://github.com/KhaosT/tb3-enabler

 

[Thinkscape]

Some fixes made in the past just involve changing a few bytes in the drivers. Just need to find them.
https://github.com/acidanthera/WhateverGreen
https://github.com/Floris497/mac-pixel-clock-patch-V2
https://github.com/KhaosT/tb3-enabler

That is indeed quite interesting... I wonder how the debugging for this goes.

Is there anyone here, following, who's got the skill set to make this happen?
(either a driver for available dongles/converters, or driver patch/workaround)

I'd be open to sponsoring such effort (even if it ends up being a binary patch that requires further maintenance)

 

[scottlilo]

I have reached out to HDfury on Discord who created the Dr HDMI 8k (reprogrammable EDID Manager) and he was kind enough to provide these values for testing, if anyone has an EDID Manager, he suggests giving this a try with a `DP -> HDMI Adapter`

the attached file is an EDID file that can be loaded into any EDID manager (From Dr HDMI, or any other)


I was hoping that the Dr HDMI 8k could be used to spoof the EDID/Timings needed to run 4k 120hz through an adaptor, but he is unsure at this point if this would be possible with his device.

I am in over my head here, but grasping at straws in attempt to help get this effort moving. I hope this is of use to someone.

 

[YoYoMa]

Apple is seriously annoying and frustrating thousands of its customers on this. It is very clearly something they should have done by now. What's even crazier is that you can't even control the volume of an HDMI connected monitor or TV from your mac, unlike literally every other device in the world, including Windows. Gives me very little faith Apple is going to get this right without massive massive massive complaints from its customers.

 

[Toss4]

Hmm going to test the latest beta to see if I can get any of my adapters to work with my M1 Max.

 

[kasakka]

Of course 120Hz or even 144Hz works via native DP.

Tell that to my 2019 16" Intel MBP. https://tonsky.me/blog/monitors-mac/ exists because support for high refresh rate 4K is a pile of crap on Macs.

Literally the same USB-C DP adapter will give me 4K 144 Hz with my PC but the same LCD display won't work at more than 4K 60 from my MBP. Meanwhile the LG OLEDs with any of the DP+DSC -> HDMI 2.1 adapters won't put out more than 4K 60 Hz.

On M1 Macs we cannot bootcamp to Windows and hence we have no proof that same hardware chain (GPU + video switcher + port controller) would allow those adapters to work, we have no definitive proof it’s being deliberately disabled via sw.

But on Intel MBPs we can and people have tested that the hardware itself is capable, MacOS isn't because of Apple's problems with software implementation. There's oh, 24 pages on this.

With Apple now having HDMI 2.1 ports on their Macs, we are hoping that this also as a side effect allows those DP adapters to work as the OS support for HDMI 2.1 should be there. I would not be surprised if they don't though.

 

[garuspl]

The PG42UQ has a 150 ppi compared to 105 ppi for the C2.

That makes a big difference long term on your eyes when reading text on the monitor/TV.

TV's usually have lower PPI for obvious reasons. The TV is just not a good idea to use it as a Monitor.

E.g on my LG OLED connected to hackintosh, anything above 1440p is horrible and frustrating to read. At the same time i still have an old 32 iMac and the text rendering and readable is far superior.

I think this is one the biggest mistake people make when buying a TV to use as a Monitor.

That's completely wrong, it's the same size, same resolution and same ratio (16:9), so the PPI is also the same. It seems you don't even know what a PPI is. It's not something arbitrarily decided - it's pixel density...

 

[ktek]

Wow wow wow, I have nothing more to add other than to say a huge thank you for the massive effort from everyone involved! I've been lurking this thread ever since the M1 Pro/Max MBPs came out and I can't believe you guys actually did it! Another success here!

For others looking to replicate, I'm using Cable Matters ver 201388 USB-C to HDMI 2.1 48 GBps adapter + UGREEN HDMI 2.1 Certified Cable. Followed the advice on this thread, flashed the custom .fullrom provided by @AironMan here for VMM6100 chips (and here for VMM7100 chips) using the Cable Matters Firmware Tool (VmmDPTool.exe), and finally followed the custom EDID instructions according to the reddit thread. It will require BetterDisplay Pro, but the cost of the upgrade sure beats a new TV or monitor!

Side note: Both my work laptop (X1 Thinkpad) and my desktop failed to open the VmmDPTool due to "Cannot find Synaptics MST DP hub IC" error, this is with the adapter connected to the pc and HDMI to the monitor. Ended up using my Steam Deck with windows 11 and it worked. Worth trying a different PC if you encounter this.

My CX48 now shows:


MacOS 13.2 now shows:


Confirming that HDR is also working with 4:4:4 10Bit:


Been more than a year since I've been able to use MacOS with that buttery 120hz and the OLED tv, once again thank you guys for the hard work!

 

[Zorast]

Get reply vom Cable Matters:

"However, since the VMM6100 chipset is discontinued, we are unable to obtain the firmware you required from the supplier. We’ll investigate why the 4K@120Hz RGB 10bit HDR works with the VMM6100 and the Firmware u send."

 

[Technotron]

Yessss, got my CM adapter - WITH the right FW. All working now, thank you so much everyone. Will stay active in this thread and keep a close eye on everything. My 50 EUR Anker adapter is going back unopened.