Author here, thanks for pointing out the mistake! The USB controller speed is indeed 4 Gbps and not 4 GB/s, I have updated the post accordingly.
> I believe the USB controller still shares a bus with the NIC, which means maxing out the network connection will affect disk rw performance. You could confirm this by observing a concurrent iperf affecting fio results.
Thanks for the pointers, I didn't know about iperf! That's something I'll likely try at some point for the sake of completeness, although I have other projects competing for my attention.
> Well, that's specifically AES precompiles. Just like for kopia, you can benchmark and change LUKS algo for something more suitable for the platform like xchacha20: https://rr-developer.github.io/LUKS-on-Raspberry-Pi/
> I believe the USB controller still shares a bus with the NIC, which means maxing out the network connection will affect disk rw performance. You could confirm this by observing a concurrent iperf affecting fio results.
Thanks for the pointers, I didn't know about iperf! That's something I'll likely try at some point for the sake of completeness, although I have other projects competing for my attention.
> Well, that's specifically AES precompiles. Just like for kopia, you can benchmark and change LUKS algo for something more suitable for the platform like xchacha20: https://rr-developer.github.io/LUKS-on-Raspberry-Pi/
Absolutely, that disk was encrypted using xchacha20. I used the excellent sdm project (https://github.com/gitbls/sdm) to make my Raspi boot from an encrypted disk. They have great documentation pointing out that xchacha20 should be used on the Pi 4 and earlier (https://github.com/gitbls/sdm/blob/master/Docs/Disk-Encrypti...)