It's not so much the microprocessor, it's all the trappings of the Arduino, and not using sleep mode. If your project is large and runs on limited battery power

It's not so much the microprocessor, it's all the trappings of the Arduino, and not using sleep mode. If your project is large and runs on limited battery power, you might want to choose another solution and work on power management. The Arduino is an excellent prototyping tool, though.