M2 MacBook Pro 2022 could not detect the second external monitor

tinh119 wrote:

I am using two external monitors; one is connected via a VGA port, and the other through an HDMI port. My M2 MacBook Pro 2022 can only detect the first external monitor connected. The second monitor never displays anything, even after I have tried various workarounds such as plugging in, plugging out, putting the computer to sleep, and using the option to detect the display. The issue persists exactly the same when I connect directly to separate Thunderbolt ports, or swap the cables/ports/adapters. It seems to behave as if there is a limit of connecting only one external monitor.

Your computer only supports one external display:

MacBook Pro (13-inch, M2, 2022) - Technical Specifications

"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"

Apple-Silicon 2020 M1 13-in MacBook Pro and Air and subsequent models with M-series (plain) processors are extremely-capable entry-level computers. They can support the internal display AND an External display up to the previously unheard of size of the Apple 6K display at billions of colors. But only ONE in addition to the internal display.

This may not match the way older computers forced you to work, since older computers were not able to support a really large external display. But it is NOT a defect. The spec was available long before you could purchase the computer.

The Apple standard for its built-in hardware-accelerated displays, makes them suitable for full-motion video for production/display of cinema-quality video with NO dropped frames, and NO dropouts or partial-blank scan lines due to memory under-runs or other issues. This requires a hardware rasterizer/display-generator for each fully-accelerated display.

If you need more hardware-accelerated displays than the built-in and ONE external display, and an un-accelerated iPad if desired, you probably need a more capable computer.

If you are doing ONLY program listings, spreadsheets, stock quotes and other slow to change data, there are some other solutions, but they require you to make some strong compromises.

Executive summary: More than ONE additional Hardware-accelerated display can NOT be added to the entry-level 13-in or 15-in M1 or M2 systems.

Grant Bennet-Alder wrote:

Apple-Silicon 2020 M1 13-in MacBook Pro and Air and subsequent models with M-series (plain) processors are extremely-capable entry-level computers. They can support the internal display AND an External display up to the previously unheard of size of the Apple 6K display at billions of colors. But only ONE in addition to the internal display.

The M3 MacBook Airs are examples of "subsequent models with M-series (plain) processors". They also have a new feature. They can drive TWO external monitors – but ONLY when the lid is closed. (In other words, there is still a limit of two display outputs; but the new machines are more "creative" about how they let you use them. If the lid is closed and the user can't see the internal display, they can "borrow" the output that they would need to drive the built-in display, and use it to drive a second external one, instead.)

A report in 9to5Mac says that Apple will be bringing the same feature to 14" M3 MacBook Pros that use the plain M3 processor (which currently have a limit of one external display) via a software patch – to be released at some unspecified date.

https://9to5mac.com/2024/03/04/14-inch-m3-macbook-pro-multi-display-support/

Servant of Cats-

You are quite correct. The original Author did not say they owned an M3 model, so I left that out.

Some Users of the base models were irate to learn that when you closed the lid on the older models, you could not re-purpose the display generator for the built-in screen to run an external screen.

Inside the computer, that takes an additional high-speed multiplexer (which adds some delay) in the data stream for the built-in display. It is possible that data rates were not quite high enough in the earlier designs to endure the additional delay. Apple eventually decided to do just that.

So YES, if you bought the M3 (base) model, you can close that lovely display you paid dearly for, and use the display generator for a second external display, INSTEAD OF (NOT in addition to) the Internal display.

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What remains to be seen is whether higher-end MacBook Pro models will carry that forward into later PRO and MAX Processor models, and allow yet another display Instead of the Built-in display if you close the lid on their built-in displays.

Grant Bennet-Alder wrote:

So YES, if you bought the M3 (base) model, you can close that lovely display you paid dearly for, and use the display generator for a second external display, INSTEAD OF (NOT in addition to) the Internal display.

Another case of Apple making things more flexible – within an overall two display limit – occurred with the Mac mini.

The M1 Mac mini, and the versions of the M2 Mac mini that have a base M2 chip, both support two displays. On the M1 Mac mini, the only way to drive two displays is by connecting one display via USB-C or Thunderbolt, and the other via the Mini's built-in HDMI port. On the M2 Mac mini, you can do that – but you can also connect two displays via USB-C or Thunderbolt (in which case you'd leave the HDMI port open).