And even the Pi 4's PCIe is fine for some things. I have a CM4-based NAS that I put together using Axzez's Interceptor board (a big thank you, Jeff: I learned about it though one of your GitHub issues where you'd been cataloging CM4 carrier boards), and it's just fine for spinning-rust hard drives. It isn't maxing out their performance or anything, but it reads and writes fast enough for anything I need to do with it.