Pushing an ILI9341 TFT to its limits with 60MHz DMA-enabled SPI on #ESP32
Correction: SPI can only run on 80/n frequencies [n between 1 and 8], so 8MHz, 8.89MHz, 10MHz, 11.43MHz, 16MHz, 20MHz, 26.67MHz, 40MHz, 80MHz . Setting SPI clock to 60MHz actually meant it got mapped to 40MHz, anything>60MHz meant setting to 80MHz. That explains the hard boundary