The Sentinel DX4000 looks good. Its black case is designed in such a way that it doesn’t seem bulky although the size is comparable to other 4-disk SOHO-class NASes: 16 x 22.5 x 20.5 centimeters. At the top of the front panel we can see a Power button, system status and HDD activity indicators, and a 2-line dot-matrix display with two buttons.
You can use the buttons to choose what information to see on the display (the NAS’s network name and address, the number of HDDs, or the available capacity).
The door of the HDD bays has a metallic grid in its center for the outside air to get into the case. The vent grid looks good with its glossy coating. There are small vents in the sides of the metallic case, too.
The back panel offers a pair of power connectors, Ethernet ports and USB 3.0 ports, a hidden Reset button, the grid of a 90mm exhaust fan, and a Kensington slot. The connectors are all at the top of the panel, so they are easy to access, but the cables aren’t going to look neat. The two power connectors are supposed to make the NAS more reliable.
The case stands on small rubber feet.
The Sentinel DX4000 doesn’t provide any normal means to dismantle the case. The HDD bays support hot swapping. You don’t need any tools to install HDDs into this NAS.
The robust metallic chassis of the NAS is riveted in most spots, so it is going to be difficult to replace or clean the cooling fan. There is a rather small PCB in the top of the case. It carries an Intel Atom D525 processor and an ICH9 chipset covered with needle-shaped heatsinks. The hardware platform is over 2 years old, by the way. The system memory consists of a single 2GB DDR3 module from Samsung in a SO-DIMM slot.
A backplane is used to connect HDDs, which is a more reliable solution than cables. The disk controllers are integrated into the chipset. USB 2.0 is ignored in this NAS, but it has an additional NEC controller that supports two USB 3.0 ports. The Ethernet controllers are based on Intel's 82574L chips. There is a single 3-pin fan connector on the PCB for the system fan.
There are several unlabeled bonding pads here but we don’t know if there is a video output among them.
While the latest top-end NASes from other brands offer VGA and HDMI, the Sentinel DX4000 is different in this respect. The lack of a video output may be due to Intel's or Microsoft's requirements concerning the use of their chips or software.
The hardware configuration is comparable to modern x86 NASes except for the lack of eSATA (the chipset might provide a couple of more ports) and video output. The latter makes it virtually impossible to run some other OS on the Sentinel DX4000.