I have a ZFS RAIDz (RAID5) array of three 7200RPM SATA2 drives in a FreeNAS virtual machine. I have multiple machines connected to this VM over a gigabit network. I'm seeing via bandwidth graphs that the gigabit network is never more than 10% saturated even when I copy a very large file off the RAID array. The peak speed I see is around 103 mbit/sec.
iperf
between the clients and the server gives between 895 and 900 Mbit/sec.
Shouldn't the read speed of a RAID5 array of 3 SATA2 7200RPM hard disk drives be able to nearly saturate a gigabit ethernet link?