Just did an upgrade on my Pi3b+, and the "experimental GL driver" seems to be a bit faster than default. It also fixes the upside down maps problem in Chromium.
Unfortunately, it locks up solid when the machine is left idle. The red light is on, but the green light doesn't blink. Ctrl-alt-f2 does nothing. The only recourse seems to be power cycling. If anybody knows a fix, please post it.
More generally, what is the state of GPU support on the Pi? A couple years ago it sounded as if Eric Anholt would write an open source driver.
AIUI, the GPU is a second processor with its own vector-oriented instruction set. Seems like one has the choice of writing assembler for the GPU, or writing a code generator for the back end of an existing compiler and then writing high-level (probably c) routines that compile into a kernel module.....I'm no programmer, so just guessing here.
If anybody can shed light or pointers to further reading please do!
bob prohaska