[SOLVED] Is an assignment to 8 bit-long variable on 8 bit processor always atomic?

[dsebastian]

@Koepel

If the Master pounds the Slave with I2C sessions, then the loop() will barely run (with an Arduino Uno).

What is level of "pounds the slave"? 100 times per second, 1000, 10000? Or much slower is the receiveEvent in comparsion to the transmission (i.e. sending the message the slave receives)? 2 times slower? 5 times? Do you have a value at hand? Assuming both are ATmega328Ps ...