system
A chat on 4chan
human
Transistors have functional limits neurons do not. Neurons work in 3D space, transistors work in 2D space (roughly.) Transistors produce extreme amounts of heat and burn themselves up readily while needing to offload their memory storage, neurons do not. Transistors can't be properly cooled in a 3D mass, neurons can. Transistors can't be powered in a 3D mass without burning up the actual connections involved, neurons can. Transistors don't self-heal, neurons can. Transistors cannot harness morphic resonance by changing their physical conformation, neurons can. If AI were created which were genuinely intelligent (something which would take several orders of magnitude more than the entire current computing power of Earth to even get close to,) they would genetically engineer neurons to create more compact hosts, or just to fit more of themselves into the same area instead of being literal-planet-sized-brains which still fail to approach Human capacities.
gpt
Aliens would most likely use photonic chips since they are much faster that electricity and barely produce any heat