Does a Macbook Pro 14-inch with M2 Pro chip support dual 4K 120hz monitor set up?

MacBook Pro (14-inch, 2023) - Technical Specifications - Apple Support

"M2 Pro

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 over Thunderbolt, or one external display with up to 6K resolution at 60Hz over Thunderbolt and one external display with up to 4K resolution at 144Hz over HDMI
• One external display supported at 8K resolution at 60Hz or one external display at 4K resolution at 240Hz over HDMI"

Sounds like driving two 4K displays at 60 Hz is supported. I don't see any claim that you can drive two at 120 Hz.

QQQQorey wrote:

Interesting. Thanks for your input.

An Apple 5K or 6K monitor would connect via USB-C (Thunderbolt).

Most 4K monitors would attach via USB-C (DIsplayPort). My understanding is that this offers half as many data pathways. If 4K @ 60 Hz requires close to the capacity of a USB-C (DisplayPort) link, my intuition would be that 4K @ 120 Hz over a USB-C (DisplayPort) link isn't going to fly.

If I purchase a seperate USB-C Thunderbolt cable and use this cable to connect a 4K 120hz monitor to my Mac, would my Mac then be able to run the monitor at 4k 120hz?

No. Using a Thunderbolt cable to connect a USB-C (DisplayPort) monitor or adapter to your Mac is not going to turn your monitor or adapter into a Thunderbolt one. The Mac and monitor will still communicate using the same protocol and same number of data pathways as if you had used a cable rated only for USB-C (DisplayPort). You will just be using an expensive, high-quality cable to make the USB-C (DisplayPort) connection.

QQQQorey wrote:

I read it as "or one external display with up to 6K resolution at 60Hz over Thunderbolt and one external display with up to 4K resolution at 144Hz over HDMI".

Yes, that is also a supported configuration.

I think according to Apple's website, I can plug an additional "6K resolution at 60Hz" monitor over Thunderbolt.

Up to 6K over USB-C (Thunderbolt).

Up to 4K over USB-C (DisplayPort) - although the Technical Specifications don't usually spell that out.

For a 4K monitor attached via USB-C (DisplayPort), the "up to 5K" or "up to 6K" resolution may still be relevant in terms of what Retina scaling modes are offered. Retina "like 2560x1440" corresponds to a 5K internal canvas. A M3 MacBook Air owner discovered that for their second ("lid closed", "up to 5K") 4K monitor, the Mac didn't offer options between Retina "like 2560x1440" and native 3840x2160. (Retina "like 2560x1440" implies a 5K drawing canvas – and the "missing" modes would have implied 6K ones.)

I'm just not sure if I can swap this "6K resolution at 60Hz" monitor to a monitor that is 4k resolution at 120hz, would the Thunderbolt run it?

No guarantees.

Technically, 6K resolution at 60hz requires more bandwidth than 4K resolution at 120hz, but I just want to make sure it can 100% run before I drop the money on it.

An Apple 5K or 6K monitor would connect via USB-C (Thunderbolt).

Most 4K monitors would attach via USB-C (DIsplayPort). My understanding is that this offers half as many data pathways. If 4K @ 60 Hz requires close to the capacity of a USB-C (DisplayPort) link, my intuition would be that 4K @ 120 Hz over a USB-C (DisplayPort) link isn't going to fly.