Apple Confirms 13″ MacBook Pro’s Thunderbolt 3 Speeds Are Reduced on One Side

Shortly after unveiling its super-advanced, late 2016 MacBook Pro with OLED Touch Bar last week, Apple released a support document covering the machine’s new Thunderbolt 3 connectivity on its website — indicating, among other things, that two of the four total Thunderbolt 3 ports on the 13-inch, Touch Bar-equipped model would not support the new uber-fast data transfer speeds.

To be more specific, the two Thunderbolt 3 ports on the right-hand side of the machine will provide users will full functionality — albeit at a reduced bandwidth capacity — while the Thunderbolt ports on the left-hand side will retain full PCIe throughput, according to AppleInsider.

Apple indicated in the Support Document that Thunderbolt 3 speeds will “vary slightly” on its 13-inch Touch Bar-equipped MacBook Pro. In comparison, however, the company’s 15-inch counterpart will boast all four Thunderbolt 3 ports featuring the full, unabridged data transfer speeds.

As AppleInsider noted, the exact infrastructure powering Thunderbolt 3 on both the 13- and 15-inch 2016 MacBook Pros remains unclear. However, it appears that the Mac-maker opted to employ a pair of two, dual-port controller chips — with one installed on either side of the machine. Apple used the most current components when building its 2016 MacBook, however, which more than likely entails that the company used Intel’s latest Alpine Ridge PCIe controllers to power its Thunderbolt 3 standard.

Interestingly enough, though, Intel currently lists multiple variants of the latest Alpine Ridge controllers on its website — offering them in single, double, and “low-energy” options — each of which apparently features a different number of PCIe lanes.

A single PCIe lane is defined by TechTarget as “a serial expansion bus standard for connecting a computer to one or more peripheral devices.” And, as such, these PCIe lanes ultimately determine the speed and quantity of data that can flow through a given PCIe channel.

Both the 13- and 15-inch MacBook Pros are capable of running a 5K display, or two 4K displays, however, so it’s reasonable to assume that the company is using two dual-port controllers — particularly in light of the fact that MacBook Pro boasts a total of four Thunderbolt ports. Therefore, without any knowledge of Apple’s exact component selection choices, one could venture to guess that the company opted to use both a standard, as well as a “low energy,” dual-port controller on each side of the machine, respectively.

Does this news affect your perception of the 13″ MacBook Pro? Let us know in the comments.