I just get my MBP 2017 with Radeon Pro 560. The system is very problematic with Metal.
First, I use the Sierra shipped with the machine and Metal 1.2 simply refuse to work. Whenever my shader reach a certain level of complexity, the app simply hung. The complexity is NOT any specific operation, only the level of combination with if-else, add/multiply/divide, sampling texture.
The I upgraded to the High Sierra beta 2. First, the app compiled by Xcode 8.3.3 still refuse to work. Then I turn to Xcode 9, and its Metal 1.2 compiler refuses to copmile the shader code. It complains some syntax error which require Metal 2.0, which was passed in Xcode 8.3.3 though. Then I turned the project to Metal 2, and this time it runs.
Everything seems fine. Only I found the frame rate is now 9 per second. I reboot the system and the frame rate goes back to 35 fps (which is normal for my app). Then if I make the system sleep or something like, the FPS is down to around 9 again until another reboot.
