I concur with Erik, I specced out a 20tb server earlier this year, matching the throughputs hits you in the wallet.
I'm amazed they are using pci-e 1x , it's kind of naive see what the guy from sun says http://www.c0t0d0s0.org/archives/5899-Some-perspective-to-this-DIY-storage-server-mentioned-at-Storagemojo.html
