You are both right and wrong, because you (and I) are not clearly distinguishing between different kinds of efficiency and effectiveness. Liquid cooling is, wi

You are both right and wrong, because you (and I) are not clearly distinguishing between different kinds of efficiency and effectiveness. Liquid cooling is, without question, more /effective/. It makes things cooler, it has a far higher capacity for heat transport. However, with /efficiency/, you do weigh the results against the effort put in: A solution is more efficient if the quotient result/effort is higher. However, in case of cooling, there are two ways to measure effort: energy expended or money expended. In the case of energy efficiency, yes, liquid cooling is better, because of the aforementioned higher effectiveness of heat transport, lesser energy expenses for pumps/fans and easier energy reuse. However, financially, all that liquid handling, custom piping, pumping, coolant, etc. is by far more expensive than a few air ducts and fans. Even with air-air heat pumps, air cooling is still less expensive, so better financial efficiency. That's why everybody is doing it as a default atm.