I'm sorry if this if off topic but I don't know a better place to put it, after it's a GPU used in Android device
My ROM maintainer has capped it at 430 mhz on the Moto z3 play. I distinctly remember it being 830 on stock, and I know the 506 clocked at 652 mhz and why would a better gpu have a much lower speed
So once and for all: what is the max clock speed of the Adreno 509?
According to Wikipedia, the "stock" clock for Adreno 509 (Snapdragon 636 SoC) is 720 MHz.
But keep in mind that this "stock clock frequency" on Wikipedia is the "stock" defined by Qualcomm, and it's extremely common that phone manufacturers define a different (higher or lower) "stock" clock for chips.
For Moto Z3 Play, the "Lenovo stock" frequency is 850 MHz, as can be seen on their website.
I have not been able to find a "max speed" of this particular GPU, probably because my Google-fu isn't powerful enough.
Q & A