The macOS Sonoma 14.6 update that Apple released today includes dual display support, an important feature specifically for the 14-inch M3 MacBook Pro. With the new software, the 14-inch MacBook Pro with M3 chip is able to run two external displays in clamshell mode, aka when the lid is closed.
Apple introduced dual display support in clamshell mode for the M3 MacBook Air models when they were released in March 2024, but at the time, the option was not available for the M3 14-inch MacBook Pro released back in October 2023. Apple said at the time that it was planning to release a software update that would add multi-display support to the M3 MacBook Pro.
The change is mentioned in Apple's macOS Sonoma update support document and in a support document on using dual monitors with the M3 MacBook Air and MacBook Pro.
The 14-inch M3 MacBook Pro now supports one external display at 6K resolution when the lid is open, or two external displays at 5K resolution at up to 60Hz when the lid is closed.
Higher-end MacBook Pro models with M3 Pro and M3 Max chips were already able to support multiple displays, so today's change only applies to the 14-inch M3 MacBook Pro model.
Aside from the display update, macOS Sonoma 14.6 addresses a number of security vulnerabilities as outlined in Apple's security support document. None of the vulnerabilities are known to have been actively exploited in the wild, but it is still a good idea to update as soon as possible.
