Mac mini(2018) isn't working with HDR

My Mac mini(2018) doesn’t have the option to turn on HDR in the settings. It should have support for HDR according to this page Play HDR video on Mac - Apple Support

Spectrum firmware: 106

Screen Shot 2022-05-26 at 3.55.14 PM

Here are the 4 cables I have used:

The Eve usb-c to usb-c cable

Thunderbolt 4 Pro Cable from Apple. (BTW the cable cost me over $170 :skull: :skull_and_crossbones:)

I’m sure I’d seen this posted before, but can’t find the old thread now…

I did some research last time I saw the old thread and from everything I could find, a Mac Mini with Intel UHD 630 graphics should be able to do HDR.

The Spectrum certain does do HDR from Intel-based Macs. I’m getting 4K @ 60Hz HDR with my 2019 MBP. Whatever the problem is, it must be specific to some combination of the Mac Mini and the Spectrum.

As you’re on firmware v106, I’ll assume that you’ve got access to Windows to do firmware updates. It’s worth trying firmware PS5.Test5 (see link below) to see if it helps out at all. It contains a change that lets DSC work over USB-C, so it’s possible that there are changes that will let HDR work correctly for you.

If you run into any issues, you can just flash v106 back onto your Spectrum.

It was the 105 firmware thread. I’m considering upgrading to the test firmware if the 107 firmware doesn’t come out for another month. My windows computer is an old dog I’d rather only drag out when I absolutely need to.

I just updated to 107 and it is still not working. It is probably related to the low channel use problem you have mentioned. I have found out that using the physical HDMI Port on my Mac into the HDMI into the EVE does allow me too use the HDR mode on Mac. But it displays some colors in adjacent pixels it is not meant for. It’s an odd behavior.

I got something going! If I use SwitchResX I am able to get HDR by setting the refresh-rate to 58Hz or lower. Not ideal but it is better then not working on DP at all.

That refresh rate makes sense. The Mini is only capable of HDMI 2.0, which means 14.4Gbps. Wikipedia has a table listing the maximum refresh rate at each resolution, including noting where subsampling kicks in. 58Hz is in the right range for 4K.

My post in the 107 firmware channel about the HBR2/HBR3 discrepancy was liked by the new firmware manager person, so hopefully it’ll be looked at for v108. Fingers crossed it solves a bunch of problems.

Geting HDR to work at 58Hz is with a USBC to DisplayPort cable, not the HDMI cable.

Odd that you need to use 58Hz for that. The HDR bandwidth requirements over DP indicate that 60Hz should be possible at HBR2 rates, if that is indeed the root cause.

I don’t have a USB-C to DP cable to check whether the primary DP ports suffer from the same issue, so what you’re seeing might be something else :frowning:

I just checked it’s the same with the thunderbolt 4 to thunderbolt 4 cable. It could be Apple’s fault. If I set the refresh rate to 50Hz the HDR option goes away the only default option that has it is 30Hz. But my custom 58Hz allows the setting. It is very weird.

I found a work around for it!
I found it here: Mac Mini 2018 - 4K only getting 4:2:2 - Apple Community
What I did was use SwitchResX to make a new “Custom Resolution”, set “Use simplified settings” set to “CVT-RB”. I made sure it was a 4k res and it chose a Vertical Hz of 60.004. Don’t know what the issue is, but was able to get it to work at 60. Will update the thread if it stops working.