Can I get 4K at 60Hz on my MacBook Air M1 with an HDMI only monitor?

AOC – AOC U2790VQ

This is a 27" 3840x2160 monitor with 10-bit-per-channel color and a maximum refresh rate of 60 Hz.

It has three video inputs:

• HDMI v1.4
• HDMI v2.0
• DisplayPort v1.2

The best way to connect it to a M1 MacBook Air would probably be with a USB-C to DisplayPort adapter or adapter cable. Your M1 MacBook Air features native DisplayPort output on its USB-C ports, even if it does not bring out the DisplayPort signal on a standard DispayPort connector.

If I remember correctly, HDMI 2.0 has bandwidth limitations that mean that you cannot have all of

• 4K resolution
• 10-bit-per-channel color
• 60 Hz refresh rate
• 4:4:4 encoding

My understanding is a bit fuzzy, but I believe that anything less than 4:4:4 encoding is basically just another way of sacrificing resolution. If you were using HDMI 2.0, your best bet might be to sacrifice 10-bit color (if you were given any choice as to what got sacrificed).

Extron – HDMI 2.0 FAQ

Still, you could get a USB-C to HDMI 2.0 adapter or adapter cable, and try using the monitor's HDMI 2.0 port.

HDMI v1.4 probably would not support 4K @ 60 Hz at all. I would recommend staying away from the HDMI 1.4 port on this monitor unless you. need to connect several devices to it at the same time.

Lubomir_Prachniar wrote:

The MBA M1 can drive a 4K display at 60Hz, but only if the correct HDMI port and cable (HDMI 2.0) are used (when laptop closed!!)...

Where does this "lid closed" come from?

MacBook Air (M1, 2020) - Technical Specifications - Apple Support

"Simultaneously supports full native resolution on the built-in display at millions of colors and: 

• One external display with up to 6K resolution at 60Hz"

5K or 6K would be over Thunderbolt, but 4K @ 60 Hz should be doable with USB-C or a USB-C adapter.

I have got 6K at 30Hz, 4K at 60Hz and 6K at 60Hz with different dongles. I think it is up to which dongle you have and what HDMI version the dongle's port has. I have the same laptop as you.

Belkin makes a USB-C to 4K HDMI 2.1 adapter. You add a quality HDMI 2.1 cable between this adapter and your display's HDMI 2.0 port.

The MBA M1 can drive a 4K display at 60Hz, but only if the correct HDMI port and cable (HDMI 2.0) are used (when laptop closed!!)...

If you want to be sure that you get 60Hz use USB-C because MacBooks tend to work more reliably with USB-C for higher refresh rates and resolutions...

😀

If I click on that link, it takes me to a login page ... must be a membership-only shopping site.

I can see UGREEN 8K 60 Hz DisplayPort 1.4 in the URL, so I'm guessing you're talking about one of these:

Amazon – UGREEN USB C to DisplayPort 1.4 Cable 8K@60Hz 4K@240Hz Unidirectional Thunderbolt 4/3 to DisplayPort Cord USB C to DP 32.4Gbps Compatible iPhone 16, MacBook Pro/Air, iPad, Mac Mini, Galaxy, XPS, 6.6FT

If so, I do not see any reason why it would not be compatible – but I would suggest limiting yourself to the 3.3 foot and 6.6 foot versions. Recent versions of macOS do not like to see display transmission errors and may cut signal if they see any; a 10 foot cable might be more likely to suffer from such errors than a shorter one.

If your link was to a DisplayPort-to-DisplayPort cable, that could still work, but you would also need a USB-C to DisplayPort (female) adapter to go with it.