M1 Mac Mini HDMI 2.1 port? DP 1.4 DSC 1.2?

[bill44]

When can we expect HDMI 2.1 on the Mac Mini?
I would like to connect a 4K 10bit 120Hz HDR monitor/OLED TV with full RGB support.
DisplayPort 1.4 and HDMI 2.0b does not have enough bandwidth to do this. Anyone know if the M1 Mac Mini supports DSC 1.2 (Display Stream Compression 1.2) which can potentially get around the issue, provided the monitor also supports it (TVs don't support DP).

Are there any Thunderbolt 3/4 to HDMI 2.1 adaptors available? I know the max bandwidth will be 40Gbps (which is enough).

 

[joevt]

The Club3d CAC-1085 is a DisplayPort 1.4 + DSC 1.2a to HDMI 2.1 adapter.

Club 3D | DisplayPort 1.4 to HDMI 4K120Hz HDR Active Adapter M/F

The Club 3D CAC-1085 is the perfect solution to connect to any HDMI™ 4K120Hz ready displays*. If you have a DisplayPort™ 1.4 ready PC or any other device that lacks the new HDMI™ 4K120Hz specification, the Club3D CAC-1085 will be the simple way to upgrade your device and connect to your new TV*...

www.club-3d.com

Use that adapter with a USB-C to DisplayPort 1.4 adapter. There's supposed to be a USB-C version (CAC-1585) but I don't know when it will be available.

The M1 Mac mini uses DSC for the XDR display so maybe it can work with the adapter? But maybe the M1 Mac has a pixel clock limit. Well, 6K 60Hz for the XDR is 1290 MHz (and supports HDR). 4K 120Hz is less than that: 1188 MHz. So if it doesn't work, then complain to Apple.

6K 60Hz with DSC uses less bandwidth than DisplayPort 1.2 HBR2 ( < 17.28 Gbps excluding overhead for wire encoding 8b/10b).

DisplayPort 1.4 bandwidth is 25.92 Gbps (excluding overhead for wire encoding 8b/10b) but DSC can triple that to 77.76 Gbps.

HDMI 2.1 bandwidth is 42.67 Gbps (excluding overhead for wire encoding 16b/18b)
DSC can triple that to 128 Gbps?

 

[matrix07]

I would guess a re-designed next version, also Apple TV next version as well.

 

[Ninja Dom]

When can we expect HDMI 2.1 on the Mac Mini?
I would like to connect a 4K 10bit 120Hz HDR monitor/OLED TV with full RGB support.
DisplayPort 1.4 and HDMI 2.0b does not have enough bandwidth to do this. Anyone know if the M1 Mac Mini supports DSC 1.2 (Display Stream Compression 1.2) which can potentially get around the issue, provided the monitor also supports it (TVs don't support DP).

Are there any Thunderbolt 3/4 to HDMI 2.1 adaptors available? I know the max bandwidth will be 40Gbps (which is enough).

What monitor/TV you got?

 

[bill44]

The Club3d CAC-1085 is a DisplayPort 1.4 + DSC 1.2a to HDMI 2.1 adapter.

Club 3D | DisplayPort 1.4 to HDMI 4K120Hz HDR Active Adapter M/F

The Club 3D CAC-1085 is the perfect solution to connect to any HDMI™ 4K120Hz ready displays*. If you have a DisplayPort™ 1.4 ready PC or any other device that lacks the new HDMI™ 4K120Hz specification, the Club3D CAC-1085 will be the simple way to upgrade your device and connect to your new TV*...

www.club-3d.com

Use that adapter with a USB-C to DisplayPort 1.4 adapter. There's supposed to be a USB-C version (CAC-1585) but I don't know when it will be available.

The M1 Mac mini uses DSC for the XDR display so maybe it can work with the adapter? But maybe the M1 Mac has a pixel clock limit. Well, 6K 60Hz for the XDR is 1290 MHz (and supports HDR). 4K 120Hz is less than that: 1188 MHz. So if it doesn't work, then complain to Apple.

6K 60Hz with DSC uses less bandwidth than DisplayPort 1.2 HBR2 ( < 17.28 Gbps excluding overhead for wire encoding 8b/10b).

DisplayPort 1.4 bandwidth is 25.92 Gbps (excluding overhead for wire encoding 8b/10b) but DSC can triple that to 77.76 Gbps.

HDMI 2.1 bandwidth is 42.67 Gbps (excluding overhead for wire encoding 16b/18b)
DSC can triple that to 128 Gbps?

Thanks joevt.
I think I'll wait for the USB-C version (CAC-1585) as the current DP version is not very elegant solution for the Mac Mini that has no DP port. Of course, at this moment in time, we don't even know if the Mac Mini supports DSC 1.2 or not.
However, native HDMI 2.1 port would be the best solution, as it does not take up a valuable TB port, supports VRR etc.

 

[bill44]

What monitor/TV you got?

LG CX 48 inch​

 

[joevt]

Thanks joevt.
I think I'll wait for the USB-C version (CAC-1585) as the current DP version is not very elegant solution for the Mac Mini that has no DP port. Of course, at this moment in time, we don't even know if the Mac Mini supports DSC 1.2 or not.
However, native HDMI 2.1 port would be the best solution, as it does not take up a valuable TB port, supports VRR etc.

I saw this YouTube video which was convincing:

It would be more convincing with a list of timings ioreg using this script:

perl script parses ioreg output, can output JSON, dumps M1 Mac display timings.

perl script parses ioreg output, can output JSON, dumps M1 Mac display timings. - ioreg.pl

gist.github.com

I got an ioreg from someone with a XDR display connected to an M1 Mac. The timings are listed at: #32 You see the 6K timing doesn't use the tiled method so it must be DSC (the XDR does not support chroma sub sampling type of compression).

For the CAC-1085, I would try the CAC-1567 or similar adapter to go with it.

 

[joevt]

I think I'll wait for the USB-C version (CAC-1585)

A USB-C to HDMI 2.1 adapter was mentioned at #62