Mac Mini M1: HDMI to HDMI or USB-C Thunderbolt > DisplayPort?

[MiniApple]

1. Once I get my M1 Mini should I connect it with HDMI to my monitor or get a USB-C to Display Port cable?
2. Is there a difference in image quality?
3. What is better or why do you recommend one solution over the other?

I will use my M1 mini for light iWorks, for surfing the web and watching iTunes series & movies. I also plan to listen to lossless music with a dedicated 7.1 headset.

I do not plan to play any games on it, as I have a Xbox for that.
My sister gifted me that monitor, so exchanging it is not an option (and it looks awesome)


Alienware 27 Gaming Monitor - AW2720HF
Device Type LED edgelight LCD monitor - 27 Inch
Panel Type Fast In-Plane Switching (IPS)
Aspect Ratio 16:9
Native Resolution 1920 x 1080 at 240Hz
Input Connectors 2 x HDMI (ver 2.0) + 1 x DP 1.2


Mac Mini M1 16 GB (ordered)
Simultaneously supports up to two displays:
One display with up to 6K resolution at 60Hz connected via Thunderbolt and one display with up to 4K resolution at 60Hz connected via HDMI 2.0


Thunderbolt 3 digital video output supports

• Native DisplayPort output over USB‑C
• Thunderbolt 2, DVI, and VGA output supported using adapters (sold separately)

HDMI 2.0 display video output

• Support for one display with up to 4K resolution at 60Hz
• DVI output using HDMI to DVI Adapter (sold separately)

 

[joevt]

DisplayPort 1.2 will allow 10 bpc while HDMI 2.0 can only do 8 bpc when doing 1080p 240Hz RGB or 4:4:4. HDMI can do 10 bpc with chroma sub sampling (4:2:2 or 4:2:0) at that refresh rate.

If you don't care about 10 bpc or if you are using 190Hz or less (which is 3 times greater than the usual 60Hz), then HDMI is fine. It will save you a USB-C port.

1440p will work well with HDMI 2.0 (up to 110 Hz for 10 bpc).
4K can work with HDMI 2.0 at 60Hz with up to 8 bpc without chroma sub sampling.

 

[Ethosik]

I am using both for two monitors. Another tip that might impact your decision, the folks at OWC verified that each Thunderbolt port on the Mac mini has its own bus/controller. Meaning hooking up a high performance display on one port will have 0 impact on the performance of the other port.

I will have one port connected to a monitor and another port connected to OWC new hub - https://eshop.macsales.com/shop/owc-thunderbolt-hub

 

[joevt]

Meaning hooking up a high performance display on one port will have 0 impact on the performance of the other port.

This is also true of Thunderbolt buses with two ports (discrete Thunderbolt 3 controllers such as Alpine Ridge and Titan Ridge) - because DisplayPort signals on one port does not affect PCIe signals on the other port. The Thunderbolt controller has separate inputs for DisplayPort (2 x (HBR2 or HBR3) x4 = 34.56 Gbps or 51.84 Gbps) and PCIe (8 GT/s x4 = 31.5 Gbps), and the Thunderbolt outputs are separate from each other. The bottleneck is that the total PCIe traffic on both ports is limited to ≈ 23 Gbps.

Integrated Thunderbolt controllers such as Ice Lake (up to four of ports), Tiger Lake, and M1 (up to two ports) have ≈38 Gbps PCIe limit total (that's a very approximate number from Ice Lake testing; not sure about M1 and Tiger Lake).

 

[Ethosik]

This is also true of Thunderbolt buses with two ports (discrete Thunderbolt 3 controllers such as Alpine Ridge and Titan Ridge) - because DisplayPort signals on one port does not affect PCIe signals on the other port. The Thunderbolt controller has separate inputs for DisplayPort (2 x (HBR2 or HBR3) x4 = 34.56 Gbps or 51.84 Gbps) and PCIe (8 GT/s x4 = 31.5 Gbps), and the Thunderbolt outputs are separate from each other. The bottleneck is that the total PCIe traffic on both ports is limited to ≈ 23 Gbps.

Integrated Thunderbolt controllers such as Ice Lake (up to four of ports), Tiger Lake, and M1 (up to two ports) have ≈38 Gbps PCIe limit total (that's a very approximate number from Ice Lake testing; not sure about M1 and Tiger Lake).

Oh good to know! I was worried if the Pro Display XDR would impact the other port's performance.

 

[coldsweat]

Not sure if its a concern/issue for you but using an HDMI cable currently removes the option to change the system font size in the 'displays' system preferences pane (larger text -> more space), whereas it reappears if you use a USB-C monitor connection. Hopefully this will be fixed in a Big Sur update

 

[joevt]

Not sure if its a concern/issue for you but using an HDMI cable currently removes the option to change the system font size in the 'displays' system preferences pane (larger text -> more space), whereas it reappears if you use a USB-C monitor connection. Hopefully this will be fixed in a Big Sur update

You mean the 5 icons "Larger Text .... More Space". That's just another method of selecting scaled/unscaled HiDPI or non-HiDPI resolutions.

Are you sure it's not missing because "Default for display" is selected?

Can you get the options back by holding the Option key and clicking "Scaled" once or twice?

If not, then post a screenshot of what you are seeing?

 

[malieckal]

I'm sending a signal to an ACD 30" (using an adapter), but unable to use a secondary display via HDMI port . . .

Anybody else have an issue using the HDMI port for a secondary display?

Thanks!

[ 2021 M1 Mini 16GB ]