SSDs have become fast, except in the cloud

This was a huge technical problem I worked on at Google, and is sort of fundamental to a cloud. I believe this is actually a big deal that drives peoples' technology directions.

SSDs in the cloud are attached over a network, and fundamentally have to be. The problem is that this network is so large and slow that it can't give you anywhere near the performance of a local SSD. This wasn't a problem for hard drives, which was the backing technology when a lot of these network attached storage systems were invented, because they are fundamentally slow compared to networks, but it is a problem for SSD.

According to the submitted article, the numbers are from AWS instance types where the SSD is "physically attached" to the host, not about SSD-backed NAS solutions.

Also, the article isn't just about SSDs being no faster than a network. It's about SSDs being two orders of magnitude slower than datacenter networks.

It's because the "local" SSDs are not actually physically attached and there's a network protocol in the way.

I suspect you must be conflating several different storage products. Are you saying https://cloud.google.com/compute/docs/disks/local-ssd devices talk to the host through a network (say, ethernet with some layer on top)? Because the documentation very clearly says otherwise, "This is because Local SSD disks are physically attached to the server that hosts your VM. For this same reason, Local SSD disks can only provide temporary storage." (at least, I'm presuming that by physically attached, they mean it's connected to the PCI bus without a network in between).

I suspect you're thinking of SSD-PD. If "local" SSDs are not actually local and go through a network, I need to have a discussion with my GCS TAM about truth in advertising.