Apple dropped Intel's integrated Iris Pro graphics in favor of
dedicated AMD graphics
across its entire
new 15-inch MacBook Pro lineup
, resulting in performance improvements over previous models. Perhaps more interestingly, the switch to AMD provides expanded external display support that desktop users have patiently waited for.
As Andrew Cunningham at
Ars Technica
explains, AMD's Polaris-based Radeon Pro 450, Radeon Pro 455, and built-to-order Radeon Pro 460 GPUs in the new 15-inch MacBook Pro support up to six displays, whereas Intel's integrated GPUs affixed to the logic board can drive a total of three displays.
The expanded support enables the new MacBook Pro to drive two of Apple and LG's new
UltraFine 5K displays
at 60Hz simultaneously. Intel's GPUs can't because, due to bandwidth limitations of the DisplayPort 1.2 spec, the two 5K displays technically function as four displays. This method is known as Multi-Stream Transport (MST).
Apple could have used Nvidia's faster Pascal-based GPUs, which support DisplayPort 1.3, but Thunderbolt 3 and most monitors do not support the higher-bandwidth spec yet. In the meantime, Nvidia's GPUs can only drive up to three displays beyond the main MacBook Pro screen — not enough for dual 5K displays over MST.
In terms of performance improvements, Cunningham benchmarked the mid-range 2.7GHz 15-inch MacBook Pro with the Radeon Pro 455 graphics chip to determine just how much faster the notebook truly is compared to the 2016 12-inch MacBook and older MacBook Pros released over the past few years.
He found the Radeon Pro 455 to be a "significant boost" over the built-to-order dedicated GPUs available in the 2012-2015 MacBook Pro models, namely the Nvidia GeForce GTX 650M, Nvidia GeForce GTX 750M, and AMD Radeon R9 M370X respectively, but said the new MacBook Pro remains unsuitable for high-end gaming and VR.
Apple officially says the 15-inch MacBook Pro offers up to 130% faster graphics performance, and up to 2.5x more computing power per watt, compared to the previous-generation 15-inch MacBook Pro, but those stats are based on the built-to-order Radeon Pro 460 chip that costs between $100 and $200 extra.
Related Roundup:
MacBook Pro 16"
Tags:
benchmarks
,
5k displays
,
AMD
Buyer's Guide:
16" MacBook Pro (Don't Buy)
Related Forum:
MacBook Pro
