Minimum delay in Arduino and RaspberryPi?

Question

Arduino

What is the minimum delay in Arduino and RaspberryPi?
1ms? Or maybe 0.1?

Answer 1

The shortest delay, this is one cycle of the processor, is implemented by the NOP (no operation) instruction.
Its duration depends on the clock frequency of the processor. And in the case of ARM, even on the mode of operation.

Answer 2

The shortest operation - writing a byte to memory on the Arduino Uno - 0.00012ms (2 cycles).