MacBook Pro With M4 Chip May Support Up to Two External Displays

Apple's upcoming entry-level M4 14-inch MacBook Pro may be capable of supporting up to two external displays with the lid open, up from one display supported in the current M3 model, if recent leaks are anything to go by.

YouTube Short by romancev768 allegedly confirming the dual display support

Apple's existing M3 14-inch MacBook Pro comes with two Thunderbolt 3 USB-C ports, not three Thunderbolt 4 ports like the 14-inch and 16-inch MacBook Pro models powered by M3 Pro and M3 Max chips.

Apart from fewer USB-C ports, the lack of Thunderbolt 4 support on the 14-inch MacBook Pro with the base M3 chip means it only supports one display with up to 6K resolution at 60Hz (or one display with up to 4K resolution at 120Hz over HDMI) when the lid is open. Currently the only way to support to two external displays simultaneously is with the lid closed, based on the resolution (up to 6K) and refresh rate (up to 60Hz) of each external display.

However, assuming the alleged Russian leaks of Apple's unannounced 14-inch MacBook Pro with an M4 chip are reliable, the new M4 variant of Apple's entry-level 14-inch MacBook Pro will come with three Thunderbolt 4 ports, as opposed to the two Thunderbolt 3 / USB4 ports found on the current model. This would mean it can support two external displays with the lid open instead of just one.

While the upgrade from two TB3 ports to three TB4 ports has yet to be confirmed, such a change would better align the entry-level machine's capabilities with Apple's more powerful MacBook Pro models.

Here's a reminder of the different display configurations possible on the M3 Pro and M3 Max models:

M3 Pro MacBook Pro:

Supports up to two external displays:

  • Two 6K displays at 60Hz over Thunderbolt, or
  • One 6K display at 60Hz over Thunderbolt and one 4K display at 144Hz over HDMI

M3 Max MacBook Pro:

Supports up to four external displays:

  • Three 6K displays at 60Hz over Thunderbolt and one 4K display at 144Hz over HDMI, or
  • Two 6K displays at 60Hz over Thunderbolt and one 8K display at 60Hz over HDMI, or
  • Two 6K displays at 60Hz over Thunderbolt and one 4K display at 240Hz over HDMI

Additional features for both M3 Pro and M3 Max:

  • Native DisplayPort over USB-C support
  • HDMI port supports either:
    • One 8K display at 60Hz, or
    • One 4K display at 240Hz

We should know for certain what the specs are for the base M4 14-inch MacBook Pro before the month is out. Apple is expected to announce new iMac, Mac mini, and MacBook Pro models with M4 chips towards the end of October, with at least some of the new Macs rumored to be released on November 1.

Related Roundup: MacBook Pro
Buyer's Guide: MacBook Pro (Neutral)
Related Forum: MacBook Pro

Popular Stories

iOS 19 Mock WWDC25 Feature

iOS 19 Expected to Run on These iPhones

Monday March 31, 2025 5:28 pm PDT by
iOS 19 will not be available on the iPhone XR, iPhone XS, or the iPhone XS Max, according a private account on social media site X that has accurately provided information on device compatibility in the past. The iPhone XR, iPhone XS, and iPhone XS Max all have an A12 Bionic chip, so it looks like iOS 19 will discontinue support for that chip. All other iPhones that run iOS 18 are expected...
maxresdefault

Apple Releases iOS 18.4 With Priority Notifications, Ambient Music, New Emoji and More

Monday March 31, 2025 10:03 am PDT by
Apple today released iOS 18.4 and iPadOS 18.4, the fourth major updates to the iOS 18 and iPadOS 18 operating system updates that came out last year. iOS 18.4 and iPadOS 18.4 come two months after Apple released iOS 18.3 and iPadOS 18.3. Subscribe to the MacRumors YouTube channel for more videos. The new software can be downloaded on eligible iPhones and iPads over-the-air by going to...
watchOS 11 Thumb 2 1

Apple Releases watchOS 11.4 With Sleep Alarm Update

Tuesday April 1, 2025 10:34 am PDT by
Apple today released watchOS 11.4, the fourth major update to the operating system that runs on the Apple Watch. watchOS 11.4 is compatible with the Apple Watch Series 6 and later, all Apple Watch Ultra models, and the Apple Watch SE 2. watchOS 11.4 can be downloaded on a connected iPhone by opening up the Apple Watch app and going to General > Software Update. To install the new software,...
AirPods Pro Firmware Feature

Apple Releases New Firmware for AirPods Pro 2 and AirPods 4

Monday March 31, 2025 11:27 am PDT by
Apple today released new firmware updates for all AirPods 4 and AirPods Pro 2 models. The new firmware is version 7E93, up from the 7B21 firmware that was installed on the AirPods Pro 2 and the 7B20 firmware available on the AirPods 4 and AirPods 4 with ANC. It is not immediately clear what new features or changes are included in the new firmware, but we'll update this article should we find ...
macOS Sequoia Feature

Apple Releases macOS Sequoia 15.4 With Mail Categorization and More

Monday March 31, 2025 10:04 am PDT by
Apple today released macOS Sequoia 15.4, the fourth major update to the macOS Sequoia operating system that launched in September. macOS Sequoia 15.4 comes two months after the launch of macOS Sequoia 15.3. Mac users can download the ‌‌macOS Sequoia‌‌ update through the Software Update section of System Settings. It is available for free on all Macs able to run macOS 15. With...
iPhone 17 Pro 34ths Perspective

iPhone 17 Pro Launching Later This Year With These 10 New Features

Sunday March 23, 2025 10:00 am PDT by
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of March 2025: Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone ...
Apple Card iPhone 16 Pro Feature

Visa and American Express Vying to Win Apple Card Deal in 'Fierce' Fight

Tuesday April 1, 2025 1:50 pm PDT by
Visa wants to pay Apple approximately $100 million to be the new payment network for the Apple Card, reports The Wall Street Journal. As of right now, the Apple Card is on the Mastercard payment network, but that is set to change because Apple is ending its partnership with Goldman Sachs. Both American Express and Visa are vying to replace Mastercard as Apple's card services provider, while...

Top Rated Comments

JackLeBoul Avatar
25 weeks ago
Yeah, it's not confusing at all.

After rereading it all, I would need a numbers spreadsheet to figure out which chip can power how many screens at what resolution at what Hz.
Score: 14 Votes (Like | Disagree)
Chancha Avatar
25 weeks ago

Does using 2 displays require so much power? Or is it just a fake limitation?
It requires actual space on the chip for dedicated display engines, which was at a premium for M1/2/3. Apple took feedback and is willing to add more of them, but as usual with chip design, it took years to realize.
Score: 11 Votes (Like | Disagree)
F23 Avatar
25 weeks ago
we are in the golden era of MacBooks
Score: 8 Votes (Like | Disagree)
AdmiralKirk Avatar
25 weeks ago
Finally. My wife’s Intel MacBook Air from early 2020 can support 2 external 4k monitors and its own.

Its not really acceptable that it has taken until q4 2024 for Arm based Mac’s to catch up ?
Score: 8 Votes (Like | Disagree)
springsup Avatar
25 weeks ago

Apart from fewer USB-C ports, the lack of Thunderbolt 4 support on the 14-inch MacBook Pro with the base M3 chip means it only supports one display with up to 6K resolution at 60Hz (or one display with up to 4K resolution at 120Hz over HDMI).

The M3 Pro-powered MacBook Pro models also support 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.
There is an important, subtle detail here: Apple seems to have intentionally degraded HDMI over USB-C, so it can’t do uncompressed 4K 120Hz 10-bit. That is only available via the built-in HDMI port, or DisplayPort over USB-C (albeit with compression that wouldn’t be needed over HDMI).

Users on these forums have discovered hacks to work around it ('https://forums.macrumors.com/threads/dp-usb-c-thunderbolt-3-4-to-hdmi-2-1-4k-120hz-rgb4-4-4-10b-hdr-with-apple-silicon-m1-m2-m3-now-possible.2381664/'). It involves buying a specific USB-HDMI adapter and flashing a custom firmware to trick the computer in to thinking it’s a DisplayPort adapter. So clearly there is no hardware limitation - it’s possible to do it, but you need to work around the fact that even as an Apple customer, Apple hates you for using a third-party monitor and will vindictively degrade your experience, and that external display support on macOS is utter trash in general. Go shopping for any USB/Thunderbolt dock and the product page will be full of caveats warning Mac users that they will have a far inferior experience than Windows users.

This should be a disclaimer on any post relating to MacBooks, especially those relating to external displays.
Score: 8 Votes (Like | Disagree)
theluggage Avatar
25 weeks ago

Apple seems to have intentionally degraded HDMI over USB-C, so it can’t do uncompressed 4K 120Hz 10-bit. That is only available via the built-in HDMI port, or DisplayPort over USB-C (albeit with compression that wouldn’t be needed over HDMI).
If DisplayPort needs compression for "4K 120Hz 10-bit" then no USB-C-to-HDMI device can officially do uncompressed 4K 120Hz 10-bit since HDMI Alt Mode is dead ('https://arstechnica.com/gadgets/2023/01/hdmi-to-usb-c-spec-axed-as-displayport-alt-mode-reigns-supreme/') and virtually everything has to go via DisplayPort alt mode or DisplayPort-over-Thunderbolt to a DP-to-HDMI converter instead - in which case any "4K 120Hz 10-bit" content has been compressed using "visually lossless" (i.e. not lossless, then) compression and anything "lost" in that process will stay lost after it is de-compressed: calling the result "uncompressed" is, well, like selling "fresh fish" when it has been previously frozen...

Not necessarily defending Apple here, but it sounds more like "nannying" by not supporting an unofficial kludge rather than an evil plan.
Score: 6 Votes (Like | Disagree)