running a checksum filesystem isn’t for the speed its for the data integrity, zfs speeds up some tasks but raw writes and suchs will always be slower due to more iops being written to the drives… also there is a 3 or 4x minimum io amplification if xattr and atime is enabled, which they are by default.
on top of that zfs will dedicated a fast area of the disk for ZIL which means doubling everything written because it will be written twice, which is pretty stupid it seems… and only way to avoid it is to have a SLOG device.
zfs really doesn’t do well in small setups.
also i stopped using rsync since my nodes are already on zfs so when i move them i used zfs send | zfs recv
which runs about 10 to 12 times faster than rsync on zfs.
what i really like about zfs is that its basically indestructible when maintained, i’m 21 months in and i have yet to loose a single byte that i didn’t delete by accident…
not for lack of disk failures and issues tho, i’ve have thousands of recorded disk errors, where zfs and redundancy saved the day