At what resolutions can the 16" 2021 M1 Max support a 120hz refresh rate on an external monitor?

Hello prabhuly1,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you have questions about the 2021 MacBook Pro and what it can support for an external monitor. Check out the technical specifications for this Mac here: MacBook Pro (16-inch, 2021) - Technical Specifications

"Simultaneously supports full native resolution on the built-in display at 1 billion colors and:

• Up to two external displays with up to 6K resolution at 60Hz at over a billion colors (M1 Pro) or
• Up to three external displays with up to 6K resolution and one external display with up to 4K resolution at 60Hz at over a billion colors (M1 Max)

Thunderbolt 4 digital video output

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

HDMI digital video output

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

We hope this helps.

Cheers!

Little additional information is provided this specification:

Refresh rates

• ProMotion technology for 'adaptive refresh' rates up to 120Hz
• Fixed refresh rates: 47.95Hz, 48.00Hz, 50.00Hz, 59.94Hz, 60.00Hz

(You may find an 'additional resource' for detail to exact info context.)

• MacBook Pro: 13, 14, and 16 inch models compared | Macworld

https://www.macworld.com/article/545699/macbook-pro-13-14-16-inch-compared-m1-m1-pro-m1-max.html

"ProMotion is a game-changer, as it brings 120Hz high refresh rates to the

MacBook Pro (finally!), but also allows for dynamic variable refresh rates

down to 24Hz, which is not only great for..."

"With ProMotion, Apple has something else up its sleeve. While rivals

have added high refresh rate screens to their laptops, these panels

can only go at one speed, all the time..

"By bringing ProMotion to the MacBook Pro, Apple could give people

all the benefits of a 120Hz screen while still keeping the incredible

battery life the M1 MacBook Pro has become known for."

..Clever thing about ProMotion is it is adaptive, so it can speed up and

slow down as required, depending on what you are doing." ~ crowded