I use this computer has a headless server that it currently has MS window server 2008 as its main operational system, installed in a ssd drive of 240 GB capacity as the main drive and 1 raid 5 (3 drive Raid) with 6 TB capacity. The server now has 16 GB of ECC RAM but plan to upgrade to another 32 GB of ECC RAM bringing my system total to 48 GB of RAM. The Seagate 4TB was put in system to transfer 1st copy backup of main mirror to expedite the transference of data. The RAID is currently been used for storage of all my virtual images and computers it also runs as a backup to my main 4TB drive (mirrored) in my main pc.
The main OS also runs Couchpotato and sickbeard and its currently running 24/7 virtual box with an ubuntu LTS server 14.x and a pfsense firewall both used for testing (I have may other virtual images that I store and run for either testing or learning). I plan to add and additional RAID 5 (4 or 5 drives have not decided yet) using WD Red Label drives.
I first used a 2750 MB but return it because it was damaged and acting up very erratically (as reviews proved to be right) I then installed a 2550 and it works like a charm!