That's a cheapo QLC drive making those numbers very conditional on several factors. Under sustained load it's not a surprise to see such drives drop to SATA speeds.

> So the limiting factor is the enclosure, that should still give me a generous 1000 MB/s.

That's capped by the USB controller, which means 512MB/s max.

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.

> The Raspberry Pi is notorious for not being excellent with encryption algorithms.

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 think you are confusing megabytes a second and megabit. Gigabit speed is approximately 125 Megabytes per second. This is close to the speed you got.

While I loved the sleuthing, I did not get why the comparison had to be between thise extreme ends of the spectrum.

Why not test a small extra cheap VPS, or, as the author does in the end, a somewhat normal PC at home?

I use several RPis of various models. But there are times when even an old Intel/AMD laptop is a more suitable solution.

I ran an 8 gig Raspberry Pi 4 with mirrored 8 TB spinning rust disks for quite a while. Performance is very good, once you stop playing with all the meta tasks and run, you know, server stuff. I ultimately switched to another system not because of CPU, but because of memory. SearXNG [1] likes a lot of memory.

[1] https://docs.searxng.org

I have 3 running. One got a RAM and SSD upgrade and serves as my desktop/media thingy/TV and mobile audio lap in my camper.