Apple updated its Touch Bar MacBook Pros last week with faster specs and quieter (and possibly more reliable) keyboards, but apparently the smaller 13-inch models also got another small boost. Now, all four of the Thunderbolt 3 ports on the 2018 models are full speed, via MacRumors.
It’s a small but useful update to the earlier 2016 and 2017 13-inch models, which only offered full-speed data on the two left-side ports, while the two right-side ports were limited to slower PCI Express bandwidth. The reason for the shift is simple: the original Intel chips on the old 13-inch MacBooks only offered 12 PCI Express lanes, which wasn’t enough for the full 40Gbps transfer speeds on all four ports.
The new eighth-generation chips on the 13-inch model now offer up to 16 PCI Express lanes, which is enough for all four ports to operate at full speed, just like its larger, 15-inch sibling.
The 13-inch MacBook Pro sans Touch Bar (oft referred to as “MacBook Escape”) only has two Thunderbolt 3 ports, so it wasn’t affected by the issue or updated as part of last week’s refresh.