For the best part of a year, on and off, I've been trying without success to get some semblance of decent performance out of some of our Android test devices.
The Note 5 has been particularly reluctant to give up the goods. I've multithreaded our engine, such that one thread does nothing but translate pre-compiled render packets into GL calls. The other thread updates the game and generates the packets, and completes well within the desired 16ms deadline.
On an iPod6 (single-threaded), framerate is nailed to 60, and the GPU time is measured at 8ms.
On the Note 5, the exact same sequence of GL calls exceeds 16ms, and fluctuates wildly. Attempting to profile it gives results like this:
Each green chunk is one frame from a static, unvarying scene. Notice how sometimes it can take two or three times as long to dispatch the exact same GL calls. Meanwhile, a hardware monitor tells me the GPU is barely ticking over, at base clock speed and 50% or lower load, and the CPU also rarely throttles anywhere near maximum.
It's almost as if the phone isn't really trying, but I can't find any clue as to what's actually going on. Help!