<human>:  I have a question about the work of john von neumann. What is the von Neumann bottleneck?
<bot>: The von Neumann bottleneck is a limitation on the speed of a computer that is caused by the need to perform a large number of operations on a single instruction. This limitation is caused by the fact that computers are made up of a large number of transistors, and each transistor can only be switched on or off. This means that a computer can only perform a limited number of operations per second.