KPTI hurts (a lot). Syscall latency and architectural impact is dramatically increased with KPTI, in large part due to the TLB flush that is typically required.

KPTI hurts (a lot). Syscall latency and architectural impact is dramatically increased with KPTI, in large part due to the TLB flush that is typically required. This is probably why AMD CPUs do not have as big of a drop; KPTI is not (urgently) necessary on AMD CPUs.