For the first time, Macs come with HDMI 2.1 ports with support for up to 4K at 240Hz or 8K at 60Hz. To achieve this level of throughput, Display Stream Compression is required.

Apple's new in-house designed M2 Pro and M2 Max SoCs are very powerful for the compact and portable form factors that they are found in; 2023 Mac mini and 2023 Macbook Pro. Apple's chips are now in some areas matching some of the most powerful chips used in PCs and exceeding them in other areas.

- "MacBook Pro now features Wi-Fi 6E for faster wireless connectivity, as well as more advanced HDMI, to support 8K displays up to 60Hz and 4K displays up to 240Hz," announced Apple.

The same is true for the M2 Pro powered 2023 Mac mini.


 The 2023 Mac Mini with M2 Pro. Photo: Apple

Using Display Stream Compression
HDMI 2.1's bandwidth (FRL) enables up to 4K 120Hz uncompressed, but video output can be pushed higher with the use of VESA's Display Stream Compression, or DSC, which is a visually lossless low-latency video compression method. 

DSC is already utilized on Nvidia's RTX 4080 and 4090 graphics cards to enable 4K 240Hz over DisplayPort 1.4a, but Nvidia's HDMI output is limited to maximum 4K 120Hz. Update: Nvidia also support 4K 240Hz over HDMI 2.1a.

The 2023 Mac mini and Macbook Pros with M2 Pro and M2 Max will not be able to run AAA games in 4K at 240fps – GPU performance estimates point to 6.8 to 13.6 TFlops. M2 Pro has up to 19 GPU cores and M2 Max up to 38 GPU cores. Many AAA games are not even available for macOS, but support for 4K 240Hz over HDMI is nevertheless a milestone that lays the foundation for much improved motion, higher video frame rates, and a much smoother overall experience as well as future devices such as the Mac Pro or even the Apple TV – just imagine that.

Now you just need to find an external monitor capable of 4K at 240Hz. This monitor must support DSC over HDMI 2.1, too.

It is worth noting that Apple's ProMotion VRR system supports up to 120Hz maximum in the 2023 MacBook Pros. The built-in LCD displays are also limited to maximum 120Hz refresh rate.

There is no mention of AV1 hardware decoding on M2 Pro and M2 Max.

The 2023 Macs support HDR10, HLG and Dolby Vision but Apple did not specify whether HDR (10-bit) is also supported for 4K 240Hz output over HDMI 2.1.


 4K 120p hits the bandwidth limit for HDMI 2.1 but 4K 240p is possible with DSC. Chart: HDMI organization