One possibility would be that biological cells just happened to be very well suited for the kind of computation that intelligence required, and even if we managed to build computers that had comparable processing power in the abstract, running intelligence on anything remotely resembling a Von Neumann architecture would be so massively inefficient that you’d need many times as much power to get the same results as biology. Brain emulation isn’t the same thing as de novo AI, but see e.g. this paper which notes that biologically realistic emulation may remain unachievable. Also various scaling and bandwidth limitations could also contribute to it being infeasible to get the necessary power by just stacking more and more servers on top of each other.
This would still leave open the option of creating a strong AI from cultivating biological cells, but especially if molecular nanotechnology turns out to be impossible, the extent to which you could engineer the brains to your liking could be very limited.
(For what it’s worth, I don’t consider this a particularly likely scenario: we’re already developing brain implants which mimic the functionality of small parts of the brain, which doesn’t seem very compatible with the premise of intelligence just being mind-bogglingly expensive in computational terms. But of course, the parts of the brain that we’ve managed to model aren’t the ones doing the most interesting work, so you still have some wiggle room that allows for the possibility of the interesting work really being that hard.)
One possibility would be that biological cells just happened to be very well suited for the kind of computation that intelligence required, and even if we managed to build computers that had comparable processing power in the abstract, running intelligence on anything remotely resembling a Von Neumann architecture would be so massively inefficient that you’d need many times as much power to get the same results as biology. Brain emulation isn’t the same thing as de novo AI, but see e.g. this paper which notes that biologically realistic emulation may remain unachievable. Also various scaling and bandwidth limitations could also contribute to it being infeasible to get the necessary power by just stacking more and more servers on top of each other.
This would still leave open the option of creating a strong AI from cultivating biological cells, but especially if molecular nanotechnology turns out to be impossible, the extent to which you could engineer the brains to your liking could be very limited.
(For what it’s worth, I don’t consider this a particularly likely scenario: we’re already developing brain implants which mimic the functionality of small parts of the brain, which doesn’t seem very compatible with the premise of intelligence just being mind-bogglingly expensive in computational terms. But of course, the parts of the brain that we’ve managed to model aren’t the ones doing the most interesting work, so you still have some wiggle room that allows for the possibility of the interesting work really being that hard.)