Using Thunderbolt 4 ports on your MacBook Pro M4 affects performance in several ways, particularly when connecting multiple monitors. Here's a detailed overview:
Thunderbolt 4 Capabilities
Thunderbolt 4 ports on the MacBook Pro M4 support up to three Thunderbolt 4 ports, allowing you to connect multiple devices, including external displays. These ports can handle up to two 6K monitors at 60Hz or one 8K monitor at 60Hz, in addition to the laptop's built-in display[2]. This is a significant improvement over previous models, as it allows for more flexible and high-resolution display configurations without needing additional adapters or software.
Bandwidth Limitations
Thunderbolt 4 offers a bandwidth of 40Gbps, which is sufficient for supporting two 4K monitors at 60Hz but may not be enough for higher refresh rates or resolutions like 4K at 120Hz[6]. For example, dual 4K at 120Hz would require roughly 50-60Gbps, exceeding the capacity of Thunderbolt 4[4]. This limitation means that if you want to achieve higher refresh rates or connect more than two 4K monitors, you might need to consider Thunderbolt 5, which is available on the M4 Pro and M4 Max models.
Display Support and Workarounds
To connect multiple monitors beyond the native support of Thunderbolt 4, you can use DisplayLink technology, which allows you to connect up to three external displays using a dock or adapter[8]. However, macOS does not support Multi-Stream Transport (MST) technology, which means that some docks and adapters may not work in extended mode over HDMI or DisplayPort without additional software or hardware workarounds[2][8].
Thunderbolt 5 for Enhanced Performance
If you have an M4 Pro or M4 Max model, you benefit from Thunderbolt 5, which offers significantly higher bandwidthâup to 120Gbpsâallowing for more demanding display configurations like triple 4K at 144Hz[1][4]. This makes Thunderbolt 5 ideal for professionals who require high-resolution, high-refresh-rate displays for tasks like video editing or 3D modeling.
In summary, using Thunderbolt 4 ports on your MacBook Pro M4 provides robust support for multiple monitors, but it may have limitations in terms of refresh rates and resolutions. For more demanding display setups, upgrading to a model with Thunderbolt 5 can offer substantial performance improvements.
Citations:[1] https://www.apple.com/newsroom/2024/10/apple-introduces-m4-pro-and-m4-max/
[2] https://plugable.com/blogs/news/plugable-products-tested-and-approved-for-the-apple-m4-macbook-pro
[3] https://www.reddit.com/r/mac/comments/1golzsa/m4_pro_and_4k120_over_thunderbolt_may_return_my/
[4] https://www.reddit.com/r/macbookpro/comments/1gqywe6/can_the_new_m4_macbook_pro_support_dual_4k/
[5] https://www.apple.com/newsroom/2024/10/new-macbook-pro-features-m4-family-of-chips-and-apple-intelligence/
[6] https://www.kensington.com/news/docking-connectivity-blog/10-things-to-know-about-thunderbolt-ports/
[7] https://sixcolors.com/post/2024/11/m4-m4-pro-macbook-pro-review-brighter-clearer-faster/
[8] https://www.macworld.com/article/675869/how-to-connect-two-or-more-external-displays-to-apple-silicon-m1-macs.html