Areca vs. ZFS performance testing.

[Andrew Snow]

ZFS does not require battery-backed disk cache, as long as disks and 
controller flush their cache when they are told to by the OS.

Then ZFS only issues sync/flush commands for the ZIL (transaction log), 
but majority of I/Os are free to sit in cache to complete when they are 
ready.  Data that is not fsync()'d by the application may be lost on 
power outage, but stuff like databases do fsync() so they are protected.

- Andrew