mbuffer
The fastest way to send data from one zfs dataset to another.
receive
sudo mbuffer -4 -s 128k -m 1G -I 9090 | sudo zfs receive -F hellcat/books
send
sudo zfs send -R tank/books@test | mbuffer -s 128k -m 1G -O 192.168.80.12:9090
Example output
in @ 0.0 kiB/s, out @ 458 MiB/s, 71.3 GiB total, buffer 14% full summary: 71.5 GiByte in 2min 48.8sec - average of 434 MiB/s