4k@144Hz no longer available after upgrade to Big Sur
 
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4k@144Hz no longer available after upgrade to Big Sur  

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joevt
(@joevt)
Noble Member
Joined: 4 years ago
 

@maraint, 95 Hz is the limit for 4K 10 bpc using HBR3 link rate without DSC. With the same link, 4K 8 bpc can go up to 118 Hz.

DSC should be able to double or triple the refresh rates.

To get the info from the display and check if DSC is being used, for Intel Macs use this:

[Please login to see this]

There may be a better method using sysdiagnose but it relies on a Core Display Debug command that is not included with macOS ( /usr/local/bin/cddebug ) I believe most of the code used by that command is in CoreDisplay framework but I'm not sure how to call it.

For M1 Macs, I made a script at https://gist.github.com/joevt/0c75b42171b3fb1a5248b4e2bee8e4d0 which gets display timing info from ioreg.

 

 

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case


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TiM
 TiM
(@tim)
Active Member
Joined: 4 years ago
 
Posted by: @maraint

 

@red_epicness, @tim and others, 

I contacted Apple technical service (maybe it's Apple Care, I don't know if there is any difference). They tell me that Macs are capped at 95Hz... 

Not sure if they were implicitly including M1 or just the previous ones, but that's what they said.  

Yeah I'd buy that. It's entirely possible that since Big Sur is engineered with the M1 Macs first and foremost in mind, and if those ones don't have the necessary GPU capacity or feature sets, then it's a completely pragmatic engineering decision to just cap the maximum refresh rate to 95Hz.

Either way, Big Sur 11.1 beta 3 should be dropping sometime this week. I'll install it when it does and report back if anything changes in there.

In any case, thanks for taking the time to talk to Apple Support and hearing what their current customer level policy is!

2017 13" MacBook Pro [7th,2C,U] + GTX 1080 Ti @ 32Gbps-TB3 (Razer Core) + Win10 [build link]  

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joevt
(@joevt)
Noble Member
Joined: 4 years ago
 

BigSur allows 1440p 144Hz on my display (Mac mini 2018 with RX 580 eGPU).

People have posted screenshots from M1 Macs showing 144Hz for 1440p displays.

The problem in Big Sur may be missing DSC support in some cases (required for 4K 144Hz). DSC is used for the XDR display at least. Not sure about other displays.

Mac mini (2018), Mac Pro (Early 2008), MacBook Pro (Retina, 15-inch, Mid 2015), GA-Z170X-Gaming 7, Sapphire Pulse Radeon RX 580 8GB GDDR5, Sonnet Echo Express III-D, Trebleet Thunderbolt 3 to NVMe M.2 case


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tanmay
(@tanmay)
New Member
Joined: 5 months ago
 

Big Sur 11.1 RC was released 2 days back. Has anyone tried to see if that fixes the issue? 

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

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Red_Epicness
(@red_epicness)
Active Member
Joined: 6 months ago
 

@tanmay, nothing change for me in 11.1 RC, sadly.

@joevt, Yeah it definately is something going on with DSC, I doubt macOS would be artificially limited to a specific framerate...

@maraint, YEs it was using 144hz HDR 10bit color 100% in catalina, I havent tried downgrading as it would take too much effort atm... 

I used Apple's TimingSnoop app (Avaliable to developers on the developer debug profile download site) for getting diagnostic information about my monitor. It clearly detects a 4k 144hz refresh rate... 

I have also started considering that it might not be the Apple silicon macs that are at fault but perhaps the new drivers for AMD's 6000 series graphics cards as those too were added in big sur as far as I am aware... Since the apple silicon drivers would probably not interact with amd drivers, the changes made to accommodate the new 6000 series might change something inadvertently.

 

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

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tanmay
(@tanmay)
New Member
Joined: 5 months ago
 
Posted by: @red_epicness

nothing change for me in 11.1 RC, sadly.

Installed the public released today (likely same build as RC) and yeah it doesn't fix the issue. I was hoping it will since the release notes mentioned it fixed some bugs for the LG 5K display.

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

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Maraint
(@maraint)
Active Member
Joined: 5 months ago
 
Posted by: @maraint

I contacted Apple technical service [...]. They tell me that Macs are capped at 95Hz... 

Well, I've reinstalled Catalina back. I had to reformat the drive to do it, as there is no way to keep anything if you have "upgraded" to Big Sur;  Time Machines backups made in Big Sur would not work in Catalina either. 

But it was worthy. Now I have 144Hz at 4k in my Macbook pro 16". Don't know what Apple technical service is thinking... 

More importantly, fan noise has reduced a lot, even dissapearing - I still select 60 or 95Hz for work, but with Big Sur they were loud even at 60Hz and low resolution. Now fans will run eventually, but they don't run just by connecting the monitor, only when you put them to make some "effort". You don't need to do a lot of "effort" though, but with this normal sstress level, they run at a very low volume level that most of the time I don't even perceive until I'm paying attention to it (is more a subtle far sound that an irritating noise now)... You'll hear them increasing the stress though and depending on the combination of resolution and ppi (and refresh rate I guess), but that was expected. 

 

 

This post was modified 5 months ago

MacBook Pro (16-inch, 2019), 2,6 Ghz 6-Core Intel Core i7, 32 Gb 2667 MHz DDR4, AMD Radeon Pro 5300M 4gb


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Maraint
(@maraint)
Active Member
Joined: 5 months ago
 
Posted by: @joevt

To get the info from the display and check if DSC is being used, for Intel Macs use this:

[Please login to see this]

 

 Thanks @joevt, I tried this, and didn't work, until I removed "-a > AGDCDiagnose_a.txt 2>&1" . Didn't return anything with this, but without it ir does. Too many things though, although i can see the DSC mentioned somewhere. Anyway, I could see that DSC was activated in the monitor's menu,  and I still wasn't able to get more that 95Hz in Big Sur. Having gone back to Catalina now I can see the 144Hz option and it works. Big Sur didn't offered anything to me but problems,  apart from a little bit more aesthetical sidebar (notifications bar). It is surely better for ARM based macs, but much worse for intel based macs. Coming back to Catalina I have won a lot (much less noise speciallly) and not lost anything. 

 

MacBook Pro (16-inch, 2019), 2,6 Ghz 6-Core Intel Core i7, 32 Gb 2667 MHz DDR4, AMD Radeon Pro 5300M 4gb


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Red_Epicness
(@red_epicness)
Active Member
Joined: 6 months ago
 

@maraint, I think you missed the file the command generates, the part you removed just saves the output to a file named AGDCDiagnose_a.txt instead out outputting to terminal. When your removed that you saw the output on the terminal. Same thing, otherwise.

 

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

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刘子琦
(@b563052622)
Active Member
Joined: 5 months ago
 

I'm getting the same issue.3440*1440,144HZ HDR 10BIT.   works fine in win10 and big sur 11.0.1.  But not with 11.1. 

Big sur 11.2 beta1 was released this moring. Have u tried it out yet?  

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

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