It sounds to me like you don't understand how little performance you actually need for this kind of stuff. People have been writing effective autopilot software for decades using hardware that wasn't even particularly fast at the time and may as well be a pile of sand today. What exactly do you think that that code needs to do? I promise that Python on a new smartphone can do way more now than we could do 20 years ago on a Pentium in C or C++. You're lucky if any of your sensors emit at even 100Hz.