Low performance on Teensy 4.1, why?

[windorey]

Hello, I have previously used a library called ILI9341_T4 on my Teensy 4.1 with an LVGL Benchmark demo and it gets average 1040 FPS, but if I use the same code and hardware, but using Arduino_GFX as my driver, I get 38 FPS average. Is this normal?

[moononournation]

Do you know the SPI speed they are running?

[windorey]

I tried 40mHz, 80mHz, 11mHz, and they all performed quite similarly on the ILI9341_T4 library but got some difference on the Arduino_GFX.

Edit: Here is a video of the LVGL Music Demo running on ILI9341_T4 library, I didn't record Arduino_GFX, but it got about 30.

[moononournation]

ILI9341_T4 seems make many optimization for LVGL, I also recommend you stick to this library if you mainly using LVGL. The main goal of Arduino_GFX is portable and compatible across multiple Arduino IDE platform. You can run same code without rewrite when you change dev device, but it is not always fastest.