1. Compound semiconductors often suffer from p-type and n-type conduction problems. Plus they're ridiculously expensive and power hungry. They also often lack a

1. Compound semiconductors often suffer from p-type and n-type conduction problems. Plus they're ridiculously expensive and power hungry. They also often lack a native oxide. 2. The problem today in CPUs is not really clock speed but much more the memory access latency, optane is much slower* than DRAM and has much lower endurance. *Even though silicon HKMG transistors use high k gate dielectrics now, they still use a silicon dioxide interfacial layer.