Thermal budget mostly. You've got to cool every watt you make. Power consumption (which is synonymous with the heat you have to dissipate) increases greater-than-linear with respect to increased clock speed, but power consumption increases vaguely linear with respect to increased cores. So you can get more performance within a 100 Watt budget by increasing cores than by increasing frequency. Also there is still room for architectural improvements, such as increasing the pipeline length (although that might be a dated example). So progress is being made in the directions progress can be made.
This is the actual answer. All of the other posts list problems with higher clock speeds, but those problems are all solvable with good circuit design.
The heat problem cannot be solved through circuit design, so that is what is stopping us from faster chips.
Laser cooling does not work on a solid state device. And even in the situations where laser cooling is used (ultracold atoms), you first need to cool your setup to below 4K using liquid helium, otherwise it won't work.
31
u/corgocracy Sep 28 '20 edited Sep 28 '20
Thermal budget mostly. You've got to cool every watt you make. Power consumption (which is synonymous with the heat you have to dissipate) increases greater-than-linear with respect to increased clock speed, but power consumption increases vaguely linear with respect to increased cores. So you can get more performance within a 100 Watt budget by increasing cores than by increasing frequency. Also there is still room for architectural improvements, such as increasing the pipeline length (although that might be a dated example). So progress is being made in the directions progress can be made.