Graph theory and computer chip design reference Wikipedia says graph theory is used in computer chip design. 

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Is there a good reference for that? I can imagine optimal way to draw cpu to chip is to draw shortest hamiltonian cycle in it.

I don't know about a reference. However, the intuition is that an electrical circuit in a computer chip design is etched into a flat surface. This implies that the graph model of this circuit must be a planar graph. So the theory behind planar graphs is very important in designing such circuits.
