Heat is a big factor, but part of limitations on speed really come from physical dimensions. At some point, speed of light travel becomes a limitation.
Also, the transistors themselves generate a lot of the heat... So you still have large amounts of heat to handle even if the interconnect traces are heatless.
> Heat is a big factor, but part of limitations on speed really come from physical dimensions.
undoubtably. We can't make things infinately fast. But being able to put the most powerful desktop processors and graphics cards we have today into a phone would definately be useful, not to mention laptops. It would also dramatically change how server farms work (their existance right now revolves around cooling, they could be so much more dense)
The transistors create a lot of heat because the current carrying capacity of the interconnect is severely limited which increases the time to switch the transistor from off to on or vv. This puts the transistor into a resistive domain where it consumes power and that leads to heat. If you use a superconducting interconnect that transition time will drop sharply and that in turn will lead to less power used by the transistor.
Also, the transistors themselves generate a lot of the heat... So you still have large amounts of heat to handle even if the interconnect traces are heatless.