Apple Silicon GPU for ARM Macs could present some problems
Apple's official move to its own processors in future Macs and MacBooks has been one of the most-talked topics in tech news for the past weeks even it has been long-rumored anyway. A victory for the ARM CPU architecture and a blow to Intel, Apple's Silicon will have repercussions for everyone involved in the Mac ecosystem in more ways than one. Some of them will be good and some will take time to be accepted. There will also be other with perhaps unseen or at least unsaid consequences, like how the new chips could drastically change the Mac's capabilities in more than just performance.
Apple has been making its own GPU silicon for years now, replacing Imagination's PowerVR that has been a staple on iPhones from the start. Driving iPhone and even iPad Pro graphics is one thing and managing desktop graphics is another. There might be some concerns about the Apple GPU's performance but that might actually be the least problematic.
Benchmarks revealed how the Apple A12Z inside Apple's Developer Transition Kit (DTK) is almost on par with integrated GPUs on Intel's and AMD's latest-gen processors. And this was still with the benchmark tool running via the Rosetta compatibility layer, which naturally incurs some performance hit. Apple's first ARM-based Macs are also expected to run on something more powerful than the Apple A12Z and have a more powerful GPU as well.
No, the problem might come from outside the GPU itself. Switching to its own ARM-based graphics microarchitecture means switching away from AMD's, NVIDIA's, and Intel's and the compatibility with peripherals that those have brought. In particular, the external GPUs or eGPUs that MacBooks finally started supporting recently may instantly become obsolete for the next generation of Apple computers.
Compatibility with peripherals and other hardware may be one of the things that will be lost in the transition to Apple Silicon. Apple has already paved the way by adding support for external drives and cameras on iPad Pros but that's only the tip of the iceberg as far as third-party devices and accessories go. Rosetta may very well provide a temporary solution but we'll have to wait and see just how far it will be able to go.