No one really knows at this time just what computational
capabilities will be required for full human-level intelligence. Ray Kurzweil
has estimated it at 20 quadrillion calculations per second. I've speculated
that he may base his estimate upon the fact that there are of the order
of a quadrillion synapses in the brain. The brain activates them about
20 times per second. One quadrillion times twenty is twenty quadrillion.
However, the activation of a synapse is probably not equivalent to a calculation.
I favor Dr. Hans Moravec's estimation..
Dr. Moravec notes that, based upon his extensive personal experience, it
would require about one billion calculations per second to emulate the
four retinal layers that pre-process optical signals before sending them
to the brain. These four retinal layers occupy a 2 cm. diameter. X 0.01
cm. volume in the retina, or about 0.03 cms3. Comparing this
to the brain, with its volume of 1,350 , yields a ratio of about
40,000. On this basis, Dr. Moravec estimates that the brain must be able
to process of the order of 100 trillion calculations per second, or about
100 times as fast as the 2005 "Cell" microprocessor, or about about 5-to-10
times what I'm guessing for the speed of the fastest 2010 "Cell" chip.
(Dr. Moravec uses 0.02 cms. for the volume of the retinal processing layers,
and 1,500 cms.for the volume of the brain, and comes up with 70 trillion
operations per second, which he rounds up to 100 trillion operations per
second, but factors of 2 are a joke when you're looking at a factor of
a 100,000:1.) In addition, I'm speculating that a mobile robot won't have
to be as capable as a human being. It won't have to perform at the near-Olympic
level of a well-trained athlete. Its vision, hearing, smell, taste, and
touch may not have to be as capable as they are in a 21-year-od human.
But the gist of the matter is that, if the "Cell" comes to fruition, we
might be approaching hardware
capabilities that can support high-level robotics sooner than we'd
expected.
Another factor that enters into these deliberations
is that the cost of RAM isn't expected to drop faster than its traditional
Moore's Law curve would indicate, and it also plays a crucial role in AI.
Dr. Moravec is currently using ~500 megabytes of RAM