Jeff Geerling also includes some interesting performance benchmarks. He was able to almost saturate the Gigabit Ethernet using NFS (106.2 MB/sec), copying a single 8GB file, but then at 17:15 in, he confesses this full speed would not remain full speed stably, but would rather sort of become slower in little fits…
Personally, I suspect those excruciatingly-cheap Kingston SSD’s being the cause of the unstable full speed.
Note: There’s also an interesting Youtube comment, warning that the Marvel SATA controller chip on the “IO Crest” (the SATA card) is known to be a bit buggy if parallel S.M.A.R.T. operations are performed on multiple RAID disks, which can possibly lock up the RAID array, requiring a reboot.