Earlier this week, the repair experts at iFixit opened up the 2018 MacBook Pro, uncovering Intel's new JHL7540 Thunderbolt 3 controller, introduced earlier this year as part of its "Titan Ridge" family.



While the specifications for the JHL7540 lists compatibility with DisplayPort 1.4 on Intel's product database, it's not as clear-cut as it sounds, as support also relies on graphics, which vary by MacBook Pro model.

MacRumors reached out to Apple for clarification. Here's what we learned:

The new 15-inch MacBook Pro with Touch Bar models support DisplayPort at High-Bit Rate 3 (HBR3), a signal standard of both DisplayPort 1.3 and DisplayPort 1.4. Apple says the dedicated Radeon Pro graphics can drive up to two 5K displays at 60Hz, each over a single stream.



The new 13-inch MacBook Pro with Touch Bar models support DisplayPort at High-Bit Rate 2 (HBR2), a signal standard of DisplayPort 1.2. This is a limitation of the Iris Plus Graphics 655 in these models, as Intel's integrated GPUs do not support DisplayPort 1.4.

What that means:

The new 15-inch MacBook Pro theoretically supports DisplayPort 1.4, which Apple confirmed, but at least for now, it still can't drive an 8K display. It could be possible with VESA's lossless Display Stream Compression standard, perhaps, but it's unclear if this can be enabled down the road.



For now, then, the new 13-inch and 15-inch models have the same compatibility with external displays as the previous-generation MacBook Pro: up to two 5K displays or up to four 4K displays on the 15-inch model, and up to one 5K display or up to two 4K displays on the 13-inch model.

For comparison, 2016 and 2017 MacBook Pro models are equipped with Intel's JHL6540 Thunderbolt 3 controller, which supports DisplayPort 1.2.

In related news, Apple has also confirmed that all four Thunderbolt 3 ports on the new 13-inch MacBook Pro with Touch Bar are now full speed, compared to only the two left-facing ports on the equivalent 2016 and 2017 models.