It's a lot harder to get the heat out. It's why we stack things like dram (HBM) or sram (AMD v-cache), and intensively used 3d in flash, but not yet heavy duty

It's a lot harder to get the heat out. It's why we stack things like dram (HBM) or sram (AMD v-cache), and intensively used 3d in flash, but not yet heavy duty processing. The more we go 3d on compute we have to cut ghz even more to reduce power, and that puts more burden on the programmer. Which we'll probably do some day.