Mac mini: 4k @ 120hz?

[joevt]

Registered to post that I found this new-ish hub from Club3D that has specifications which might seem promising: https://www.club-3d.com/en/detail/2597

I reached out to their support asking about compatibility with an 16" M1 Max MBP. I highly doubt this will work given the findings here, but I may just grab it to add another data point for the discussion.

You mean this? https://www.club-3d.com/en/detail/2...d_2xusb_type_c_data_and_pd_charging_100_watt/
It probably uses a Synaptics DisplayPort 1.4 MST Hub which supports HBR3 link rate and DSC.
Since it supports USB 3.x, it means the MST hub's input has only two lanes of DisplayPort. Not helpful if DSC doesn't get enabled by macOS.
AllRez (from an Intel Mac) will tell you which Synaptics MST Hub is being used.

 

[sig_kill]

You mean this? https://www.club-3d.com/en/detail/2...d_2xusb_type_c_data_and_pd_charging_100_watt/
It probably uses a Synaptics DisplayPort 1.4 MST Hub which supports HBR3 link rate and DSC.
Since it supports USB 3.x, it means the MST hub's input has only two lanes of DisplayPort. Not helpful if DSC doesn't get enabled by macOS.
AllRez (from an Intel Mac) will tell you which Synaptics MST Hub is being used.

That's the one yep - looks like I truncated the link in my post.

I'm not sure how macOS decides when DSC should be enabled for a display or not... would that done when reading the device EDID?

 

[joevt]

That's the one yep - looks like I truncated the link in my post.

I'm not sure how macOS decides when DSC should be enabled for a display or not... would that done when reading the device EDID?

For HDMI 2.1 connection, I think the EDID is the place to look. I don't think any Macs with a GPU that has a HDMI 2.1 port will do DSC that way. So that leaves DisplayPort. For DisplayPort the DSC info is in the DPCD registers. It's like EDID but only for DisplayPort connections. AllRez parses DPCD. EDIDUtil.sh can extract EDID's from AllRez output and use edid-decode to parse all the EDIDs that are found.

In macOS Catalina, seeing DSC support in the DPCD may be sufficient to enable DSC. Apple changed that in BigSur and later. They might require an override file with DisplayPort/DisableDSC=0. These fields exist in the override files for the Apple Pro Display XDR but not the Apple Studio Display even though I think the Apple Studio Display does use DSC?

I created the modified WhatEvergreen/Lilu to make testing this possible. It forces the overrides to be read from the /Library/ folder instead of the /System folder so that the override file can be more easily modified (since macOS doesn't allow users to change files in /System). But it hasn't been tested to have an effect yet. I'll try tomorrow with some adapters that support DSC (I don't have a display that supports DSC by itself).

 

[jdjingdian]

Just install Ventura beta2 on another patition. And with the same VMM7100 adapter, both of them can run in 4K120 HDR mode.
I leave my monitor at office, will try your new patch later.
@joevt

 

[ThisOneHere]

I bought from here: https://item.taobao.com/item.htm?spm=a1z09.2.0.0.319e2e8d1utA4B&id=669805172547&_u=nr31tgc4890
View attachment 2022426
I guess it is the same as CableMatters (Model No. 201388).

Interesting thread. I have the CableMatters 201388 adapter (VMM 6100 chipset) + MacBook Pro M1 Pro running macOS Ventura 13.0 Beta 2. As expected, still not able to get above 60Hz on my 42" LG C2 w/ HDMI 2.1 cable.

I noticed comments stating the unit pictured appears to provide 4K 120Hz option w/ Intel MBP. I was able to find what looks to be the same item on Amazon (search for "APEXSUN USB C to HDMI 8K HDR Adapter" or "B09VNQ58L2"). Ordered it to see if it comes with VMM 7100 chipset, and if it performs any differently on M1. Will report back once it arrives tomorrow.

 

[threeseed]

Interesting thread. I have the CableMatters 201388 adapter (VMM 6100 chipset) + MacBook Pro M1 Pro running macOS Ventura 13.0 Beta 2. As expected, still not able to get above 60Hz on my 42" LG C2 w/ HDMI 2.1 cable.

I noticed comments stating the unit pictured appears to provide 4K 120Hz option w/ Intel MBP. I was able to find what looks to be the same item on Amazon (search for "APEXSUN USB C to HDMI 8K HDR Adapter" or "B09VNQ58L2"). Ordered it to see if it comes with VMM 7100 chipset, and if it performs any differently on M1. Will report back once it arrives tomorrow.

Can you get 4K / 60Hz ?

I can't even get that with the same setup.

 

[ThisOneHere]

Can you get 4K / 60Hz ?

I can't even get that with the same setup.

Yes 4K@60Hz works fine. Did you set the HDMI input icon to PC, and enable “4K” setting for HDMI Deep Color (Settings > General > Devices > HDMI settings)?

 

[joevt]

Just install Ventura beta2 on another patition. And with the same VMM7100 adapter, both of them can run in 4K120 HDR mode.
I leave my monitor at office, will try your new patch later.
@joevt
View attachment 2023392

Ventura has a few improvements shown in the AllRez outputs compared to the outputs from Monterey.

While you're playing with other OSs, I would try Catalina to see if DSC is enabled by default for any of the adapters.


Ventura changes for q80t

It seems you are using different settings for the q80t. VRR is removed in the latest EDID. I guess this doesn't matter if the adapter doesn't allow VRR. There's also some new modes in the EDID:

    VIC   7:  1440x480i   59.940060 Hz  16:9     15.734 kHz     27.000000 MHz
    VIC  22:  1440x576i   50.000000 Hz  16:9     15.625 kHz     27.000000 MHz
    VIC   3:   720x480    59.940060 Hz  16:9     31.469 kHz     27.000000 MHz
    VIC  18:   720x576    50.000000 Hz  16:9     31.250 kHz     27.000000 MHz

Ventura adds 4K100 and 4K120 modes (both HDMI timings with 1188 MHz) which were missing in Monterey. Associated scaled modes are also added except where a non-scaled mode of the same refresh rate exists. Actually, it's weirder than that. For example, 1440p120 scaled mode is added for HDR but the corresponding SDR mode is not a scaled mode. For your built-in display, no new modes are added.

Ventura does not add 8K scaled modes as Monterey does for either display. I guess they're redundant since the display is only 4K (or less than 4K in the case of the built-in display) but one might prefer the anti-aliasing that using 8K provides - or the ability to take 8K HiDPI screenshots.

Ventura fixes a bug in the maxBandwidth calculation of IOFBTimingRange. The corrected bandwidth is 25.79 Gbps which is the HBR3 max of 25.92 Gbps with allowance for some small amount of overhead I guess (but smaller than I would expect). It increases the dscMaxSlicePerLine from 4 to 8. It sets the dsc bpp range to 0 instead of 6..63. I'm not sure why they did that. Maybe because Apple always uses a default of 12bpp? Unless that's been changed...

For the built-in display, it says the maxBandwidth is 100.8 Gbps. I don't understand this. The DPCD only reports 4 lanes of HBR2 which is 17.28 Gbps. For the built-in display, the dsc bpp range is still 6..63. The built-in display doesn't support DSC. Actually, the IOFBTimingRange for all the IOFramebuffers that don't have a display connected are the same as that of the built-in display. Maybe 100.8 Gbps is the total max bandwidth of all displays?

One thing interesting about Synaptics adapters is that they have some kind of console text output happening in the Branch Device-Specific section of the DPCD. You can see this better with the firmware update app you can get from the Microsoft Store for Windows (search for Synaptics). I should see if I can get the full console text log in AllRez...

There's a strange bug in the DPCD for the built-in display reported in the AGDCDiagnose output included the AllRez output for the q80t. All the bytes for Reg: 000080 to Reg: 00008f are 00 but it reports something different for Reg: 000082. The same AGDCDiagnose output is missing DPCD for the adapter/external display even though AllRez was able to report the DPCD.

The AGDCDiagnose output has some minor updates in Ventura.

AGDC Power Mode    0 (Default Power)
Workload Policy    8 (Multi-Display)

Reported Link Rate    HBR2 - 5400 Mbps/lane
Reported Link Spread    YES
Dongle Type    None (0)
DPCD version    0x12
Sink Count    1
Supports VRR    NO

Link Rate (Mbps/lane)    5400 (max:5400)

It says your builtin display is outputting 10bpc in Ventura, but the framebuffer is only 8bpc. Use the SwitchResX menu to change the framebuffer depth to billions of colors.

My parsing of GTRACEDATASTREAM for Ventura is missing all the things that are specific to Monterey. I would have to update it for every version of AGDCDiagnose. Well, I don't think GTRACEDATASTREAM has very useful info anyway...


Ventura changes for r648

- Adds 4K120 4:2:0 10bpc 1188MHz (17.82 Gbps) mode and associated scaled modes.
- No 4K110 mode is added in this case, unlike the q80t.
- 2560x1080@100Hz 4:4:4 10bpc is removed.
- 2560x1440@120Hz 4:4:4 497.75MHz is upgraded from 8bpc to 10bpc. This means that this mode can also do HDR now.
- 8K scaled mode removed (also for built-in display)
- Recognizes display as 7680x4320 instead of 4096x2160.
- Sets maxBandwidth in IOFBTimingRange is calculated as 25.79 Gbps (only for r648, other IOFramebuffers now have 100.8 Gbps)
- Sets max slices per line to 8 instead of 4
- Sets dsc bpp range to 0 instead of 6..63 (only for r648, other IOFramebuffers still have 6..63)

AllRez got an error trying to read DisplayPort DPCD for the display. Maybe I should add a retry.

AGDCDiagnose parses more registers:

Built-in display:
- Reg: 002210: 00 : FEATURE_ENUMERATION_LIST: VSC_SDP_EXTENSION_FOR_COLORIMETRY_SUPPORTED 0

r648 display:
- Reg: 002210: 08 : FEATURE_ENUMERATION_LIST: VSC_SDP_EXTENSION_FOR_COLORIMETRY_SUPPORTED 1
- Reg: 000082: 00 : DETAILED_CAP_INFO_AVAILABLE: MAXIMUM_BPC: 8 bpc, MAXIMUM_LINK_BW: Not Suppported, SOURCE_CONTROL_MODE: Not Supported, CONCURRENT_LINK_BRINGUP: Not Supported
- Reg: 003036: 7f : HDMI_ENCODED_LINK_BW: 0x7f HDMI_LINK_CONFIG: FRL mode, HDMI_ENCODED_LINK_BW: 09/18/24/32/40/48 Gbps
- Reg: 00303b: 00 : HDMI_TX_LINK_STATUS: HDMI_TX_LINK_ACTIVE_STATUS 0, HDMI_TX_READY_STATUS 0
- Reg: 00305a: 00 : HDMI_FRL_LINK_CONTROL_1: FRL_MAXIMUM_ENCODED_LINK_BW_ENABLE Not Suppported, SOURCE_CONTROL 0, CONCURRENT_BRINGUP 0, FRL_MODE_ENABLE 0, FRL_HPD_READY_STATUS 0, HDMI_LINK_ENABLE 0
- Reg: 00305b: 00 : HDMI_FRL_LINK_CONTROL_2: FRL_ENCODED_LINK_BW_MASK  Gbps, FRL_LINKTRAIN_CONTROL Extended

AGDC removes parsing of some registers:

r648 display:
- Reg: 000080: 08 : DETAILED_CAP_INFO_AVAILABLE: DWN_STRM_PORTX_CAP: [0] DisplayPort, DWN_STRM_PORTX_HPD: 1, NON_EDID_DWN_STRM_PORTX_ATTRIBUTE: 0 
- Reg: 000084: 00 : DETAILED_CAP_INFO_AVAILABLE: DWN_STRM_PORTX_CAP: [0] DisplayPort, DWN_STRM_PORTX_HPD: 0, NON_EDID_DWN_STRM_PORTX_ATTRIBUTE: 0 
- Reg: 000088: 00 : DETAILED_CAP_INFO_AVAILABLE: DWN_STRM_PORTX_CAP: [0] DisplayPort, DWN_STRM_PORTX_HPD: 0, NON_EDID_DWN_STRM_PORTX_ATTRIBUTE: 0 
- Reg: 00008c: 00 : DETAILED_CAP_INFO_AVAILABLE: DWN_STRM_PORTX_CAP: [0] DisplayPort, DWN_STRM_PORTX_HPD: 0, NON_EDID_DWN_STRM_PORTX_ATTRIBUTE: 0

I think parsing of Reg: 000082 is broken.

Built-in display:
- Reg: 000082: 00 : DETAILED_CAP_INFO_AVAILABLE: MAXIMUM_BPC: 8 bpc, MAXIMUM_LINK_BW: Not Suppported, SOURCE_CONTROL_MODE: Not Supported, CONCURRENT_LINK_BRINGUP: Not Supported

I believe AllRez parses those registers correctly already (I don't have DisplayPort 1.4 spec, I'm just going by what's in the Linux source code).
AllRez DPCD output is cleaner because it usually doesn't show registers that are zero unless zero has a meaning other than "does not exist".

 

[jdjingdian]

Ventura has a few improvements shown in the AllRez outputs compared to the outputs from Monterey.

While you're playing with other OSs, I would try Catalina to see if DSC is enabled by default for any of the adapters.


Ventura changes for q80t

It seems you are using different settings for the q80t. VRR is removed in the latest EDID. I guess this doesn't matter if the adapter doesn't allow VRR. There's also some new modes in the EDID:

    VIC   7:  1440x480i   59.940060 Hz  16:9     15.734 kHz     27.000000 MHz
    VIC  22:  1440x576i   50.000000 Hz  16:9     15.625 kHz     27.000000 MHz
    VIC   3:   720x480    59.940060 Hz  16:9     31.469 kHz     27.000000 MHz
    VIC  18:   720x576    50.000000 Hz  16:9     31.250 kHz     27.000000 MHz

Ventura adds 4K100 and 4K120 modes (both HDMI timings with 1188 MHz) which were missing in Monterey. Associated scaled modes are also added except where a non-scaled mode of the same refresh rate exists. Actually, it's weirder than that. For example, 1440p120 scaled mode is added for HDR but the corresponding SDR mode is not a scaled mode. For your built-in display, no new modes are added.

Ventura does not add 8K scaled modes as Monterey does for either display. I guess they're redundant since the display is only 4K (or less than 4K in the case of the built-in display) but one might prefer the anti-aliasing that using 8K provides - or the ability to take 8K HiDPI screenshots.

Ventura fixes a bug in the maxBandwidth calculation of IOFBTimingRange. The corrected bandwidth is 25.79 Gbps which is the HBR3 max of 25.92 Gbps with allowance for some small amount of overhead I guess (but smaller than I would expect). It increases the dscMaxSlicePerLine from 4 to 8. It sets the dsc bpp range to 0 instead of 6..63. I'm not sure why they did that. Maybe because Apple always uses a default of 12bpp? Unless that's been changed...

For the built-in display, it says the maxBandwidth is 100.8 Gbps. I don't understand this. The DPCD only reports 4 lanes of HBR2 which is 17.28 Gbps. For the built-in display, the dsc bpp range is still 6..63. The built-in display doesn't support DSC. Actually, the IOFBTimingRange for all the IOFramebuffers that don't have a display connected are the same as that of the built-in display. Maybe 100.8 Gbps is the total max bandwidth of all displays?

One thing interesting about Synaptics adapters is that they have some kind of console text output happening in the Branch Device-Specific section of the DPCD. You can see this better with the firmware update app you can get from the Microsoft Store for Windows (search for Synaptics). I should see if I can get the full console text log in AllRez...

There's a strange bug in the DPCD for the built-in display reported in the AGDCDiagnose output included the AllRez output for the q80t. All the bytes for Reg: 000080 to Reg: 00008f are 00 but it reports something different for Reg: 000082. The same AGDCDiagnose output is missing DPCD for the adapter/external display even though AllRez was able to report the DPCD.

The AGDCDiagnose output has some minor updates in Ventura.

AGDC Power Mode    0 (Default Power)
Workload Policy    8 (Multi-Display)

Reported Link Rate    HBR2 - 5400 Mbps/lane
Reported Link Spread    YES
Dongle Type    None (0)
DPCD version    0x12
Sink Count    1
Supports VRR    NO

Link Rate (Mbps/lane)    5400 (max:5400)

It says your builtin display is outputting 10bpc in Ventura, but the framebuffer is only 8bpc. Use the SwitchResX menu to change the framebuffer depth to billions of colors.

My parsing of GTRACEDATASTREAM for Ventura is missing all the things that are specific to Monterey. I would have to update it for every version of AGDCDiagnose. Well, I don't think GTRACEDATASTREAM has very useful info anyway...


Ventura changes for r648

- Adds 4K120 4:2:0 10bpc 1188MHz (17.82 Gbps) mode and associated scaled modes.
- No 4K110 mode is added in this case, unlike the q80t.
- 2560x1080@100Hz 4:4:4 10bpc is removed.
- 2560x1440@120Hz 4:4:4 497.75MHz is upgraded from 8bpc to 10bpc. This means that this mode can also do HDR now.
- 8K scaled mode removed (also for built-in display)
- Recognizes display as 7680x4320 instead of 4096x2160.
- Sets maxBandwidth in IOFBTimingRange is calculated as 25.79 Gbps (only for r648, other IOFramebuffers now have 100.8 Gbps)
- Sets max slices per line to 8 instead of 4
- Sets dsc bpp range to 0 instead of 6..63 (only for r648, other IOFramebuffers still have 6..63)

AllRez got an error trying to read DisplayPort DPCD for the display. Maybe I should add a retry.

AGDCDiagnose parses more registers:

Built-in display:
- Reg: 002210: 00 : FEATURE_ENUMERATION_LIST: VSC_SDP_EXTENSION_FOR_COLORIMETRY_SUPPORTED 0

r648 display:
- Reg: 002210: 08 : FEATURE_ENUMERATION_LIST: VSC_SDP_EXTENSION_FOR_COLORIMETRY_SUPPORTED 1
- Reg: 000082: 00 : DETAILED_CAP_INFO_AVAILABLE: MAXIMUM_BPC: 8 bpc, MAXIMUM_LINK_BW: Not Suppported, SOURCE_CONTROL_MODE: Not Supported, CONCURRENT_LINK_BRINGUP: Not Supported
- Reg: 003036: 7f : HDMI_ENCODED_LINK_BW: 0x7f HDMI_LINK_CONFIG: FRL mode, HDMI_ENCODED_LINK_BW: 09/18/24/32/40/48 Gbps
- Reg: 00303b: 00 : HDMI_TX_LINK_STATUS: HDMI_TX_LINK_ACTIVE_STATUS 0, HDMI_TX_READY_STATUS 0
- Reg: 00305a: 00 : HDMI_FRL_LINK_CONTROL_1: FRL_MAXIMUM_ENCODED_LINK_BW_ENABLE Not Suppported, SOURCE_CONTROL 0, CONCURRENT_BRINGUP 0, FRL_MODE_ENABLE 0, FRL_HPD_READY_STATUS 0, HDMI_LINK_ENABLE 0
- Reg: 00305b: 00 : HDMI_FRL_LINK_CONTROL_2: FRL_ENCODED_LINK_BW_MASK  Gbps, FRL_LINKTRAIN_CONTROL Extended

AGDC removes parsing of some registers:

r648 display:
- Reg: 000080: 08 : DETAILED_CAP_INFO_AVAILABLE: DWN_STRM_PORTX_CAP: [0] DisplayPort, DWN_STRM_PORTX_HPD: 1, NON_EDID_DWN_STRM_PORTX_ATTRIBUTE: 0
- Reg: 000084: 00 : DETAILED_CAP_INFO_AVAILABLE: DWN_STRM_PORTX_CAP: [0] DisplayPort, DWN_STRM_PORTX_HPD: 0, NON_EDID_DWN_STRM_PORTX_ATTRIBUTE: 0
- Reg: 000088: 00 : DETAILED_CAP_INFO_AVAILABLE: DWN_STRM_PORTX_CAP: [0] DisplayPort, DWN_STRM_PORTX_HPD: 0, NON_EDID_DWN_STRM_PORTX_ATTRIBUTE: 0
- Reg: 00008c: 00 : DETAILED_CAP_INFO_AVAILABLE: DWN_STRM_PORTX_CAP: [0] DisplayPort, DWN_STRM_PORTX_HPD: 0, NON_EDID_DWN_STRM_PORTX_ATTRIBUTE: 0

I think parsing of Reg: 000082 is broken.

Built-in display:
- Reg: 000082: 00 : DETAILED_CAP_INFO_AVAILABLE: MAXIMUM_BPC: 8 bpc, MAXIMUM_LINK_BW: Not Suppported, SOURCE_CONTROL_MODE: Not Supported, CONCURRENT_LINK_BRINGUP: Not Supported

I believe AllRez parses those registers correctly already (I don't have DisplayPort 1.4 spec, I'm just going by what's in the Linux source code).
AllRez DPCD output is cleaner because it usually doesn't show registers that are zero unless zero has a meaning other than "does not exist".

Test with the new Lilu/WhateverGreen on 12.4, still got 4k60.
I'm curious about why there is 6720x3780 mode in the output.

 

[joevt]

Test with the new Lilu/WhateverGreen on 12.4, still got 4k60.
I'm curious about why there is 6720x3780 mode in the output.

6720x3780 is just a scaled mode. Scaled modes are automatically added by macOS. A corresponding 3360x1890 HiDPI mode is also added, just as the 5120x2880 scaled mode causes a 2560x1440 HiDPI mode to be added.

It appears that only the patch enabled by the -cdfon boot-arg (for WindowServer/CoreDisplay framework) was enabled. This patch includes a pixel clock patch (165MHz DVI limit changed to 400MHz) for Nvidia GPUs and a CoreDisplay patch that causes it to test all modes against the driver (instead of skipping them). But this patch is not what is needed for the modes we want (since the driver incorrectly does not validate some of the modes).

The patch enabled by the -dpdon boot-arg (for displaypolicyd) does not appear to get enabled or it gets enabled after the Lilu log ends (not likely).
I think maybe the only way to know for sure that it's enabled is to run the following command, and see if anything appears when you connect a display:
sudo detruss -n displaypolicyd 2>&1 | grep "Overrides"
With the patch, it should say "/Library/...
Without the patch it should say "/System/Library...

For some reason, displaypolicyd doesn't read overrides for my MacPro3,1 (Nivida Kepler), iMac14,2 (Nivida Kepler), or iMac17,1 (RX580). Maybe because they're old GPUs? But RX580 is new enough to fill the detailed timing information with color depth and encoding (unlike the older GPUs).

Compared to your previous Lilu test, the new one adds these 16:10 aspect ratio scaled modes:
2048x1280
2880x1800
3360x2100
3840x2400
Does this mean CoreDisplay doesn't usually allow 16:10 modes for a 16:9 display?

 

[ThisOneHere]

Not able to get 4K@120Hz on either my 55" LG CX or my 42" LG C2. I've tried Monterey 12.4 and Ventura 13.0 Beta 2, on both an M1 MacBook Pro M1 Pro, and a 2019 iMac 27" with i9 CPU and Radeon Pro 580X GPU. I have attempted with CableMatters 201388 adapter (VMM 6100 chipset), and the same adapter "jdjingdian" states works (VMM 7100 chipset - found on AMZN by searching for "B09VNQ58L2").

4K HDMI Deep Color setting and PC mode icon are enabled, and I tried using two different HDMI 2.1 certified cables. 4K@60Hz w/ or w/o HDR work fine, as do 2560*1440 or 1920*1080 @ 120Hz on both adapters and TVs.

What am I missing? "jdjingdian" provided pics but I'm not able to replicate.

EDIT: Should add that I installed SwitchResX Beta on Ventura and don't see the option for 4K @ 120Hz there either.

 

[desert0616]

Not able to get 4K@120Hz on either my 55" LG CX or my 42" LG C2. I've tried Monterey 12.4 and Ventura 13.0 Beta 2, on both an M1 MacBook Pro M1 Pro, and a 2019 iMac 27" with i9 CPU and Radeon Pro 580X GPU. I have attempted with CableMatters 201388 adapter (VMM 6100 chipset), and the same adapter "jdjingdian" states works (VMM 7100 chipset - found on AMZN by searching for "B09VNQ58L2").

4K HDMI Deep Color setting and PC mode icon are enabled, and I tried using two different HDMI 2.1 certified cables. 4K@60Hz w/ or w/o HDR work fine, as do 2560*1440 or 1920*1080 @ 120Hz on both adapters and TVs.

What am I missing? "jdjingdian" provided pics but I'm not able to replicate.

EDIT: Should add that I installed SwitchResX Beta on Ventura and don't see the option for 4K @ 120Hz there either.

This is just an unfounded speculation.

Only the intel-based macbook pro 16 inch has managed to achieve 4k120. Someone in this thread has tried m1-based as well as the early mbp15 (rx560x), both without success.

Therefore, the m1 pro you mentioned does not work as expected. imac2019 may be because the rx5xx GPU does not meet the requirements (such as this model would not have supported hdmi2.1?).

 

[jmole]

This is just an unfounded speculation.

Only the intel-based macbook pro 16 inch has managed to achieve 4k120. Someone in this thread has tried m1-based as well as the early mbp15 (rx560x), both without success.

Therefore, the m1 pro you mentioned does not work as expected. imac2019 may be because the rx5xx GPU does not meet the requirements (such as this model would not have supported hdmi2.1?).

The 14/16" MacBook Pro M1 both work with native DisplayPort 4K120 Displays. Like the Acer XV273K.

They should also work on an HDMI 2.1 display when using an active DisplayPort/HDMI converter, like this one by UpTab or this one by Club 3D.

Both of these have ICs inside that convert the DisplayPort signal (with or without DSC, etc.) to HDMI 2.1.

The problem is not on the hardware side, there is something funny going on in the macOS display drivers preventing you from using these adapters at 4K120.

 

[threeseed]

They should also work on an HDMI 2.1 display when using an active DisplayPort/HDMI converter, like this one by UpTab or this one by Club 3D.

The CableMatters 201388 should also work as it gets 4K/120Hz with Windows.

But we all know it doesn't on M1 Macs.

 

[zamzam1235]

Just install Ventura beta2 on another patition. And with the same VMM7100 adapter, both of them can run in 4K120 HDR mode.
I leave my monitor at office, will try your new patch later.
@joevt
View attachment 2023392

So with this setup. Are you getting the proper HDR and SDR brightness in mac os as compared to windows.

I am using Monterey and even though i am only doing 4k/60 Hz, the brightness in macos is very dull compared to my windows. Windows even at 4k/60 hz give a nice crisp bright display, while mac os is dull. I tried correcting the gamma as well , but stil mac os looks ****.

Can you please check if the desktop brightness is same as windows in ventura Beta 2?

 

[jdjingdian]

So with this setup. Are you getting the proper HDR and SDR brightness in mac os as compared to windows.

I am using Monterey and even though i am only doing 4k/60 Hz, the brightness in macos is very dull compared to my windows. Windows even at 4k/60 hz give a nice crisp bright display, while mac os is dull. I tried correcting the gamma as well , but stil mac os looks ****.

Can you please check if the desktop brightness is same as windows in ventura Beta 2?

Sorry, I dont use windows for a while. I think you can try Better Display (formerly known as "Better Dummy"). The developer said it can " NEW! Reach the full brightness potential of your XDR or HDR display! * "

 

[zamzam1235]

Sorry, I dont use windows for a while. I think you can try Better Display (formerly known as "Better Dummy"). The developer said it can " NEW! Reach the full brightness potential of your XDR or HDR display! * "

Fantastic utility. Helped with the HDR brightness at little, but now the colors are somewhat washed out. played around a lot to get the brightness just right , but not quite there with what windows gives.

Another big problem now i have is i m used to the AMD's vivid color enhancement which makes color just vibrant enough and looks absolutely fantastic. This will be a big miss in mac os even though i ' m connected with the same AMD 6800 xt. wish we radeon adrenaline for mac also.

So we have two main issues which i highly doubt apple will ever fix.

1. Native HDR brightness control in macos.
2. Digital vibrancy.

Hope someone more experienced in apple macos can shed some light on this. It just horrible that i can't utilize my LG OLED and AMD card to full capabilities in macos , while windows does it in a breeze. It's sad for people using mac mini's with external displays and e-gpus.

 

[svandive]

I think my hdmi2.1 adapter is using Synaptics VM7100.
And recently I always run my mbp in clamshell mode.
View attachment 2022147

What model adapter are you using? I've been looking around for one that is confirmed to be based on the he VMM 7100 chip. Thanks,

 

[jdjingdian]

What model adapter are you using? I've been looking around for one that is confirmed to be based on the he VMM 7100 chip. Thanks,

See #430
"I noticed comments stating the unit pictured appears to provide 4K 120Hz option w/ Intel MBP. I was able to find what looks to be the same item on Amazon (search for "APEXSUN USB C to HDMI 8K HDR Adapter" or "B09VNQ58L2"). Ordered it to see if it comes with VMM 7100 chipset, and if it performs any differently on M1. Will report back once it arrives tomorrow."

 

[DaSal]

The 14/16" MacBook Pro M1 both work with native DisplayPort 4K120 Displays. Like the Acer XV273K.

They should also work on an HDMI 2.1 display when using an active DisplayPort/HDMI converter, like this one by UpTab or this one by Club 3D.

Both of these have ICs inside that convert the DisplayPort signal (with or without DSC, etc.) to HDMI 2.1.

The problem is not on the hardware side, there is something funny going on in the macOS display drivers preventing you from using these adapters at 4K120.

So is Ventura officially ‘supposed’ to fix this software limitation in the macOS display drivers, or are we actually hoping for a surprise undocumented change?

 

[joevt]

So is Ventura officially ‘supposed’ to fix this software limitation in the macOS display drivers, or are we actually hoping for a surprise undocumented change?

Officially? That would require Apple to say something. Fat chance. That would require admitting some deficiency in previous OS. And as far as Apple is concerned everything is working as expected.

All we know is what differences we can detect between running Ventura and running an older OS. I think DSC is still disabled by default since after Catalina but that would require someone to get output from Catalina so it can be compared.

 

[onlinespending]

Officially? That would require Apple to say something. Fat chance. That would require admitting some deficiency in previous OS. And as far as Apple is concerned everything is working as expected.

All we know is what differences we can detect between running Ventura and running an older OS. I think DSC is still disabled by default since after Catalina but that would require someone to get output from Catalina so it can be compared.

How does one enable DSC manually, then? Thanks

 

[joevt]

How does one enable DSC manually, then? Thanks

Not sure yet. I suspect for Intel Macs that my OpenCore/Lilu/WhateverGreen can make displaypolicyd load override files from /Library instead of /System. If you put DisplayPort/DisableDSC = 0 and DisplayPort/DisableFEC = 0 in an override file for your display, then maybe it will enable DSC but I haven't tested this yet. Sometimes (usually?) my displaypolicyd patch causes macOS boot to not complete. I think the verbose log output shows an error regarding displaypolicyd but it scrolls by too fast to see. So I'm trying to get macOS logging output to serial port using a PCIe serial card connected to Thunderbolt, but only the OpenCore and xnu early init serial output is appearing. Maybe I should try FireWire or Ethernet instead of serial...

There's some interesting things in Ventura for displaypolicyd. It can load separate override files for dongles (which appear to only include the DisplayPort/DisableFEC and DisplayPort/DisableDSC fields). Such files don't actually exist but they could in the future. It has specific code for the Dell UP3218K which seems to limit dual tile support to MacPro7,1 (using the board-id). It has some new error messages that don't exist in Monterey or earlier.

 

[zamzam1235]

Finally got the DisplayPort to Hdmi cable. Cable used is

8K DisplayPort to HDMI Cable 6.6ft, ULT-WIIQ DP 1.4 to HDMI 2.1 Video Cable, Support 8K, 4K@120Hz/144Hz, 2K@240Hz, Dynamic HDR, Dolby Vision, HDCP 2.3, DSC 1.2a for PC, HP, DELL, AMD, NVIDIA Graphics​

From amazon.

First the good news.

I m able to get 4k 120hz ycbcr420 with HDR

Now the bad part.

with chroma subsampling its horrible.

Now with full chroma

I m able to get full chroma at 4k 30hz only , not even at 60 hz which should be possible with DisplayPort bandwidth.

Is there anyway to get ycbcr444 @ 4k/60 hz?

I tried EDID modification, but it only allows me to remove YCbCr 444 and 420 modes and force RGB only which is only 8 bit. no HDR.

 

[kasakka]

I m able to get full chroma at 4k 30hz only , not even at 60 hz which should be possible with DisplayPort bandwidth.

Is there anyway to get ycbcr444 @ 4k/60 hz?

I tried EDID modification, but it only allows me to remove YCbCr 444 and 420 modes and force RGB only which is only 8 bit. no HDR.

Because Apple's external display support is a pile of crap, the only way I found to get 4K 60 Hz 4:4:4 on my LG CX 48" was to disable 10-bit color with EDID modification. Otherwise it would always just use 4:2:0. Even before the EDID mod HDR working was hit or miss.