Cannot Connect More Than 2 External Monitors to MacBook Pro M3

The same rules we learned for the M1 and M2 still apply. Display interfaces are generated deep inside the system on a chip. How many there are depends on the exact type of Processor:

M3 (plain) like the 13-in and 15-in supports up to ONE fully hardware-accelerated external display.

M3 PRO processor supports up to Two fully hardware-accelerated external displays.

M3 MAX processor supports up to Four fully hardware-accelerated external displays.

In every case, turning off the internal display does Not allow you to connect another external display.

Tech Specs now available here:

MacBook Pro - Tech Specs - Apple

Grant Bennet-Alder wrote:

The same rules we learned for the M1 and M2 still apply. Display interfaces are generated deep inside the system on a chip. How many there are depends on the exact type of Processor:

M3 (plain) like the 13-in and 15-in supports up to ONE fully hardware-accelerated external display.

M3 PRO processor supports up to Two fully hardware-accelerated external displays.

M3 MAX processor supports up to Four fully hardware-accelerated external displays.

f you throw in the desktops, you can generalize the rules. I.e., M2 supports up to two displays total – including any built-in one. (Which jibes with the M2 Mac mini supporting two external displays – while 13" and 15" M2 MacBook Airs and 13" M2 MacBook Pros support only one.)

In every case, turning off the internal display does Not allow you to connect another external display.

That's true of current Apple Silicon MacBook Pros – and of most Apple Silicon notebooks and iMacs, period.

The 13" and 15" MacBook Airs are an exception. They can drive a second external display (with lower maximum resolution) when, and only when, their lids are closed. (The lower 5K resolution limit may translate into not being able to use any Retina mode higher than "like 2560x1440" with a 4K monitor.)

News reports say that Apple plans to bring that feature to the 14" M3 MacBook Pro via a software patch. There isn't any announced date for the release of this patch, and for now, the limit for the 14" M3 MacBook Pro is ONE external display.

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.

MacBook Pro M3 (base) models with 14-in display supports the same ONE external display.

On the MacBook AIR M3 (base) models with 13-in or 15-in displays, 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.

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.

mdm-0199 wrote:

It's absolutely unacceptable that a Macbook of any kind cannot support extending two external monitors with the laptop open. I have a Dell PC that is 10 years old that can support that setup. The limitation here is mind-boggling. If anyone has a work around please post here. Hoping apple can release an update...

Apple, and other computer manufacturers, make computers with varying specifications. The user needs to review the specifications prior to purchase to ensure they are buying the computer that meets their needs. It is not the computer manufacturer's fault if the purchaser buys a computer that does not meet the requirements for the user needs. The same applies to to all computer purchasers regardless of computer brand.

JMRIII wrote:

I don’t think it’s his fault that he didn’t review the technical specs. There is a ton of on-line info that says it can.

There is a lot of misinformation online. Why would you take the word of some random Web site over information on the manufacturer's own Web site that clearly states the limitation?

Only MacBook Pros with the “Pro” or Pro Max” chips can support more than one external monitor. This is pathetic - after all this is the “Pro” model.

MacBook Pros with base M1, M2, and M3 chips are conceptual descendants of low-end 13" MacBook Pros from the Intel days. Those MacBook Pros had only two Thunderbolt ports, and, I think, had older-generation Intel processors than the 13" MacBook Pros that had four Thunderbolt ports.

Once MacBook Airs got Retina displays, 13" MacBook Pros with only two Thunderbolt ports were very similar to MacBook Airs, and a case could have been made for eliminating the low-end 13" MacBook Pros. Apple did not eliminate them, and they remained in the product line.

If Apple got rid of 14" M3 MacBook Pros that have the plain M3 chip, and offered only M3 MacBook Airs and M3 {Pro/Max} MacBook Pros, there would be a clearer separation between the MacBook Air and Pro lines. For some strange reason, I get the feeling that even if there was a clear separation, that wouldn't satisfy you.

As noted, the most basic Dells have had this capability for over a decade. Support for 2 external monitors should be available on any MacBook.

If you want to provide feedback to Apple, you are free to do so.

Product Feedback - Apple

in order to support up to TWO displays on one cable out of the Mac, the Port, the Cable and the first device (Dock or Display) must all be genuine Thunderbolt.

USB-C has fewer conductors, and does not support the same amount of data.

There is no “workaround” or “update” that can add more first-class, hardware-accelerated display outputs. As far as I can tell, all Apple Silicon Macs using the same chip have very consistent specifications for the number of displays they support, when you adjust for built-in displays.

Ir is your fault if you did not review the Technical Specifications available before purchase. They do not spell out all corner cases, but would have kept you from making the mistake of buying a Mac that could not support as many external displays as you say you want.

It's absolutely unacceptable that a Macbook of any kind cannot support extending two external monitors with the laptop open. I have a Dell PC that is 10 years old that can support that setup. The limitation here is mind-boggling. If anyone has a work around please post here. Hoping apple can release an update...

I don’t think it’s his fault that he didn’t review the technical specs. There is a ton of on-line info that says it can. Even when I called Apple technical support they initially said it could and had me try various things to try and get it to work before telling me oops it can’t support more than one external monitor. Only MacBook Pros with the “Pro” or Pro Max” chips can support more than one external monitor. This is pathetic - after all this is the “Pro” model. As noted, the most basic Dells have had this capability for over a decade. Support for 2 external monitors should be available on any MacBook.

I asked about trading in on a MacBook Pro machine that will support this capability and they offered me 40% of what I paid for the machine 4 months ago. Again pathetic.