The chart is showing data from an NFS copy, but the listed speeds in the blog and on github[1] are from a copy on a local SSD. That is a bit confusing though, maybe I should make it more clear. I used the network copy for ETA calculation because it was an easy way to make the transfer take longer - if the whole copy is only a few seconds long it's difficult to meaningfully compare ETA estimation accuracy between two approaches. I would like to have more performance data though.