As desktop processors were first crossing the Gigahertz level, it seemed for a while that there was nowhere to go but up. But clock speed progress eventually ground to a halt, not because of anything to do with the speed itself but rather because of the power requirements and the heat all that power generated. Even with the now-common fans and massive heatsinks, along with some sporadic water cooling, heat remains a limiting factor that often throttles current processors.
Part of the problem with liquid cooling solutions is that they';re limited by having to get the heat out of the chip and into the water in the first place. That has led some researchers to consider running the liquid through the chip itself. Now, some researchers from Switzerland have designed the chip and cooling system as a single unit, with on-chip liquid channels placed next to the hottest parts of the chip. The results are an impressive boost in heat-limited performance.
This seems like a very logical next step for watercooling and processor cooling in general, but this is far from easy. This article highlights that we are getting closer, though.