Mac mini: 4k @ 120hz?

[iTTT]

so does this mean that even i have a RX 6900 XT + LG C2 OLED TV, both have HDMI 2.1, i still cannot make macOS to achieve 4K 120hz ?

thanks

 

[desert0616]

so does this mean that even i have a RX 6900 XT + LG C2 OLED TV, both have HDMI 2.1, i still cannot make macOS to achieve 4K 120hz ?

thanks

no, you cannot.

for TVs (with only HDMI ports), there is no solution to get more than 4k60 (8bitrgb or 10bit420) on macOS.

 

[Viper11]

And I suppose that get 5-6K at 60fps it's also impossible.

 

[desert0616]

And I suppose that get 5-6K at 60fps it's also impossible.

seems no product you mentioned (5-6k hdmi) on the market. and for apple, you cannot say anything before an experiment ...

 

[Viper11]

seems no product you mentioned (5-6k hdmi) on the market. and for apple, you cannot say anything before an experiment ...

I've got a 8K Samsung TV and If I can reach 6K from M1 with some adapters, maybe worth it.
Problem it's purely subjective and visual. I usually switch from a windows computer using 8K and when I see screen on Mac, it's hurts justs a tiny bit.

 

[threeseed]

And I suppose that get 5-6K at 60fps it's also impossible.

Studio Display (5K at 60Hz) and Pro Display XDR (6K at 60Hz).

There are rumors Pro Display will move to 7K at 60fps (or 6K at 120Hz) but that might be M1/M2 Mac Pro only (will need DP 2.0 support).

Some bandwidth calculations here if you're interested:

Pro Display XDR at 120Hz bandwidth calculations

Pro Display XDR at 120Hz bandwidth calculations. GitHub Gist: instantly share code, notes, and snippets.

gist.github.com

 

[joevt]

There are rumors Pro Display will move to 7K at 60fps (or 6K at 120Hz) but that might be M1/M2 Mac Pro only (will need DP 2.0 support).

That article says 6K120 works with DSC@8bpp. HBR3 has enough bandwidth to do 6K120 with DSC@9bpp. You can increase DSC bpp by sixteenths of a pixel so it could be anywhere between 9bpp and 10bpp. macOS uses DSC@12bpp but there's a setting to change that called "DSCtargetBPP". #172 I don't think anyone has reported trying it yet.

EDIT (Oct 3, 2024):
Turns out that the dscTargetBPP preference can only be changed if the Apple Internal SIP bit is set, and that bit cannot be set by csrutil. I don't know how to change that bit.

My WhateverGreen fork (Intel Macs only) has a new patch to change dscTargetBPP (add a boot-arg dscbpp=8 - for Catalina and later). If you're using Open Core or OCLP, then you can replace Lilu and WhateverGreen with my versions. If you use any other Lilu based kexts then they need to be recompiled using the headers from my Lilu.kext. That patch, in conjunction with the CheckTimingWithRange patch (add a boot-arg -cdfon - For Tiger and later), can enable 4K240 and beyond on Intel Macs with a GPU that supports DSC (tested with 6800XT and Sequoia). DP to HDMI adapters are not tested.

I think Apple Silicon Macs automatically support DSC with values ≤ 12 (4K240 tested on M3 with Sequoia).

 

[joevt]

M1 Macs get variable refresh rate (Adaptive Sync, AMD FreeSync, not sure about GSync displays). I haven't seen it work on Intel Macs yet. I think I have a display that supports VRR (Acer XV273K) but my Mac mini 2018 with Radeon Pro W5700 doesn't show a VRR option. Maybe I need a different GPU or VRR isn't support on Intel Macs.
https://arstechnica.com/gadgets/2021/10/macos-12-monterey-the-ars-technica-review/10/ says it works on Intel Macs. So I guess I should try my RX 580 instead of the W5700...

Correction: The VRR option shows in the above setup for the 1080p and 1440p options but not for 2160p options - maybe because 2160p is limited to 120Hz while the Max refresh rate for VRR on the display is 144Hz. So what's a good test of this VRR option? The display has a refresh rate overlay but it doesn't seem to change from 144Hz (or 72Hz in some cases).

The timing for VRR is 1080p or 1440p (real timings - not scaled modes or HiDPI modes). I can add other VRR resolutions (720p, 1908p, etc.) as long as their max refresh rate is near 144Hz. The corresponding HiDPI modes for those timings will have a VRR option.

The EDID doesn't seem to change when FreeSync is disabled/enabled in the display's menu. In either case the EDID shows 40-144Hz refresh rate range (AMD VSDB)

The DPCD has MSA_TIMING_PAR_IGNORED: 1 in reg 000007h when FreeSync is enabled. When it is being used, the DPCD also has MSA_TIMING_PAR_IGNORE_EN: 1 in reg 000107h.

Variable refresh rate modes are indicated in AGDCDiagnose as VB Extension > 0. AllRez shows vbext > 0.

 

[joevt]

So what's a good test of this VRR option? The display has a refresh rate overlay but it doesn't seem to change from 144Hz (or 72Hz in some cases).

Screensavers: Flurry, Arabesque, and Shell have variable refresh rate. Click Preview to make them fullscreen, then the display's refresh rate overlay will start changing rapidly.

 

[JakeXXX]

So just for clarification’s sake, if I daisy chain a USB C to DisplayPort 1.4 dongle into a DisplayPort 1.4 to HDMI 2.1 dongle—that doesn’t work? Or is it worth a try?

 

[JakeXXX]

I will confirm for final clarification on my Sony X900H 4K120Hz TV and LG C1 OLED.

HyperDrive 8k HDMI 2.1 -> TB4 limited to 4k60Hz.

Converting HDMI 2.1 to DisplayPort 2 or 1.4 to TB4 does not work. It does however register a DisplayPort audio signal and two alternate 60Hz viewing modes, one I suspect is VRR but still outputs at only 60Hz.

SwitchResX will determine 4K@120Hz resolutions invalid. I cross referenced the pixel clock was running at on my Windows RTX 3090 rig for maximum support. Did not work.

To sum up the last 15 pages of this thread: until Apple releases HDMI 2.1 support, no 4k@120Hz on HDMI 2.1 devices. Just a ton of Amazon returns for me

 

[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.

 

[SuckOr]

It is as frustrating with Ultrawide Displays and Scaling… I am thinking about going back to Windows.

 

[kasakka]

So just for clarification’s sake, if I daisy chain a USB C to DisplayPort 1.4 dongle into a DisplayPort 1.4 to HDMI 2.1 dongle—that doesn’t work? Or is it worth a try?

No that does not work either. I've tried Cablematters USB-C to DP 1.4 -> Club3D CAC-1085 DP to HDMI 2.1 -> LG CX 48" and no go. The exact same dongle configuration works without problems from my desktop PC's 2080 Ti's USB-C port.

It seems to me that this issue will not be resolved until Apple themselves add a HDMI 2.1 port and thus need to actually solve the compatibility with that. I fully expect that won't happen until maybe next year if even then considering the new Mac Studio is only HDMI 2.0 as well. Apple is either jumping the gun for new ports or taking forever to add them.

For now the only way to get above 4K @ 60 Hz on MacOS is by using USB-C/TB -> Displayport connection, which TVs just don't have unfortunately.

 

[ThatPineapple]

No that does not work either. I've tried Cablematters USB-C to DP 1.4 -> Club3D CAC-1085 DP to HDMI 2.1 -> LG CX 48" and no go. The exact same dongle configuration works without problems from my desktop PC's 2080 Ti's USB-C port.

It seems to me that this issue will not be resolved until Apple themselves add a HDMI 2.1 port and thus need to actually solve the compatibility with that. I fully expect that won't happen until maybe next year if even then considering the new Mac Studio is only HDMI 2.0 as well. Apple is either jumping the gun for new ports or taking forever to add them.

For now the only way to get above 4K @ 60 Hz on MacOS is by using USB-C/TB -> Displayport connection, which TVs just don't have unfortunately.

I can also confirm this setup doesn't work with my 14" M1 MBP. The exact same setup works in getting 4k@120Hz with my 2019 16" MBP connected to a LG CX 48". It's definitely an Apple Silicon limitation, not a MacOS limitation.

 

[abbihaus]

Hi All,

I've just ordered an LG C1 48 OLED to power my mac as a primary monitor but I'm worried I've messed up after reading these issues.

Just to clarify, I don't care about 4k @ 120hz but I do care about 120hz. What are my options in terms of resolutions to support this?

I'm coming from a 34inch UW monitor so I UW would be ideal but 1440p is also fine. Could I do 1600p ultrawide @ 120hz?

Thanks!

 

[Monstieur]

Hi All,

I've just ordered an LG C1 48 OLED to power my mac as a primary monitor but I'm worried I've messed up after reading these issues.

Just to clarify, I don't care about 4k @ 120hz but I do care about 120hz. What are my options in terms of resolutions to support this?

I'm coming from a 34inch UW monitor so I UW would be ideal but 1440p is also fine. Could I do 1600p ultrawide @ 120hz?

Thanks!

You can do 2560x1440 8-bit RGB 144 Hz on HDMI 2.0. You'd need a custom EDID for any 1600p resolution but there should be enough bandwidth for at least 120 Hz.

macOS will also run only at 4:2:0 with no way to change it to RGB. You need this patch to force RGB mode, which also disables HDR as macOS doesn't support 8-bit RGB HDR with dithering:

patch-edid.rb

GitHub Gist: instantly share code, notes, and snippets.

gist.github.com

 

[threeseed]

Just to clarify, I don't care about 4k @ 120hz but I do care about 120hz. What are my options in terms of resolutions to support this?

I'm coming from a 34inch UW monitor so I UW would be ideal but 1440p is also fine. Could I do 1600p ultrawide @ 120hz?

It is a 48 inch monitor and so everything will be huge at 1440p unless you are sitting like 2m away from it. I run mine at 3008 by 1692 pixels which is the best choice for size/quality for me. But at that resolution it's 60Hz + HDR.

Also Monstieur forgot to mention that the EDID option doesn't work on any M1 Mac.

Apart from the Pro Display XDR which is perfect for Macs everything else comes with their own pros/cons. C1 has great blacks, the size is very useful but the text lacks clarity and it's only 60Hz.

 

[Monstieur]

I wouldn't buy it if you're restricted to 4:2:0 on the desktop on M1 Macs because the RGB patch doesn't work. It looks terrible.

 

[kasakka]

I can also confirm this setup doesn't work with my 14" M1 MBP. The exact same setup works in getting 4k@120Hz with my 2019 16" MBP connected to a LG CX 48". It's definitely an Apple Silicon limitation, not a MacOS limitation.

Really? You can get it working on an Intel MBP? I just tried with my 2019 16" Intel MBP using the afore-mentioned dongles and 4K 60 Hz is the best it can do. Even lower resolutions don't offer 120 Hz.

 

[Monstieur]

Really? You can get it working on an Intel MBP? I just tried with my 2019 16" Intel MBP using the afore-mentioned dongles and 4K 60 Hz is the best it can do. Even lower resolutions don't offer 120 Hz.

2560x1440 8-bit RGB 120 Hz works fine on Intel MBPs.

 

[QuietOC]

My 14" M1 Pro runs both my 55" LG C1 and 55" Samsung QN90A 1440p at 120 Hz directly from HDMI. It looks full chroma to me with HDR enabled.

 

[desert0616]

while.. it seems that even many guys submit the feature requests to apple .. there is nothing going to change .. sad ..

 

[threeseed]

I used to work at Apple and they do look at Radar for advice about how serious an issue is.

So please do file reports at: https://developer.apple.com/bug-reporting/

 

[iTTT]

anyone try macOS Ventura?