Max RPM Stock Magnum Rods

Sorry, I think it is the amount of power and torque being forced on the rods. The more rpm, the more stress it will see. However, I think the amount of stress is different between a 300 hp engine and a 600hp engine. The higher the HP, the more stress it see at a given rpm. And to further complicate matters, I’m sure the break point of power, torque & RPM will be at a lower rpm with the higher hp engine. How is that for variables?