Using Serial.print() without a serial connection == slow performance?

[mzincali]

Hi. I have a board that was custom designed. I am using the built-in JTAG/USB wired from the ESP32 to the USB connector as how I upload code and see printouts via Serial.print() to the Arduino IDE console (I still have not figured out how to see the same console info on PlatformIO, like i used to with standard ESP32 dev boards).

One thing I have noticed is that when I unplug the USB, and run the same program, everything seems to slow down and take longer. I can't tell, obviously, what is going on since I don't have prints to the console happening.

What I do know is that I commented out all my Serial.print() lines and tried it all again and didn't have the same delays anymore. Is this a known thing? Is this just an Arduino issue? Does using ESP32 native logging instead of Serial.print() work better?

Thank you!

[ESP_Sprite]

Could be a bug in the Arduino code that checks if it can write data to the USB-serial-JTAG... If this is reproducible, you may be better off filing this as an issue on the Arduino-esp repo.

[mzincali]

Looks like it's a bug.

https://github.com/espressif/arduino-es ... 1184671948