Western Digital Sentinel DX4000

Western Digital Sentinel DX4000 4TB

The four-bay, $900 (as of March 23, 2012) Western Digital Sentinel DX4000 4TB is the only NAS box we've tested recently that uses Microsoft's Storage Server 2008 R2 Essentials for its operating system. All other comers are Linux-based, which turns out to be a big advantage. Despite being a well-conceived piece of hardware, the Sentinel DX4000 doesn't deliver enough performance or features to compete head-to-head with the speed demons we've seen from QNAP and Synology. Not a company that's content to step back in time, Western Digital has equipped the DX4000 with state-of-the-art, trayless, quick-change bays (simply slide in the drives), dual gigabit ethernet ports, and two USB 3.0 ports. Pairing ethernet ports provides failover protection in case one connection goes down, but the NAS box doesn't support aggregation for increased performance. USB 3.0 means faster local backup of the box, but the absence of eSATA might kill the deal for prospective buyers who want to use existing eSATA drives to back up the DX4000. The WD's NAS box even has dual AC jacks, though it ships with just one power brick. Microsoft's Storage Server 2008 R2 Essentials is much easier to install than Windows Home Server, an OS that some cheaper NAS boxes have employed in recent years.