HI,
I have a Due and a tft display using a ST7789 driver. I find its quite slow at display even simple strings. i was originally trying to have a realtime readout of an encoder but the update speed is just too slow. I got close by just updating the text rather than refreshing the entire screen but its still way too slow. I am aware of a ST7789 fast library but its optimised for a AVR chips not the dues ARM chip. it didnt seem to work even in compatibility mode. anyone got any ideas ? can modify the adafruit st7789 library to get the transfer faster ?