Not sure why people are simply downvoting you without answering your question. Apple shipped its first in-house GPU with the A11 Bionic in the iPhone 8/8+/X, and by all accounts it’s a marvel of engineering and quite fantastic for a first outing.

And you’re right - a look at the developer docs for Metal do show that ‘this matters’

[1] https://techcrunch.com/2017/09/12/the-new-iphone-8-has-a-cus... [2] https://developer.apple.com/documentation/metal/about_gpu_fa...