Mac hardware
Do M1s have Thunderbolt 3 or 4? We help to solve your hardware hassles, from interrupted upgrades to running diagnostics
QDoes my M1 iMac have two Thunderbolt 3 or 4 ports?
A
Strictly speaking, the two Thunderbolt ports on M1 Macs are Type 3 with added support for USB4, which is one of the requirements for Thunderbolt 4. Apple’s wording isn’t as precise as it could be, referring to ‘Thunderbolt/USB 4’, which appears ambiguous.
The main requirements for Thunderbolt 4 over those for 3 include support for USB4 (whose official name doesn’t have a space), a minimum bandwidth of 32Gbps over its PCIe link, DisplayPort 1.4 with its support for dual 4K displays, and protection against physical security attacks using an Intel system.
While it’s possible that the ports on M1 Macs reach those requirements for minimum bandwidth and displays, M1 Macs don’t support two external displays (without additional peripherals) because of other hardware limitations in their display controller. As Thunderbolt is implemented within the M1 chip and doesn’t use any Intel hardware in Apple silicon Macs, it seems unlikely that it can meet the requirement for security protection either.
One practical feature which comes with Thunderbolt 4 is the ability to use external hubs offering more than two Thunderbolt ports, which is true for M1 models. It’s perhaps most useful to consider the M1 as having Thunderbolt 3 ports which also support USB4 and external Thunderbolt hubs, perhaps as Thunderbolt 3.5. There are advantages in buying cables certified for Thunderbolt 4, as they should work better, particularly in two-metre lengths; Thunderbolt 3 cables don’t always work well with USB-C devices.