Mediasonic Probox 8-bay 3.5" USB 3.0 / eSATA DAS Reviewby Ganesh T S on August 4, 2012 7:55 AM EST
Build Quality and Internals:
The Mediasonic Probox 8-bay JBOD enclosure comes in a spartan package with just the bare necessities. The most important aspect of the package is the absence of an external power adapter. The PSU is internal to the unit. The contents of the package are as below:
- Probox main unit
- 1x eSATA cable
- 1x USB 3.0 cable
- 1x power cord
- 8x plastic HDD handles and 16x screws for the handles
- 2x keys for the door to the HDD bays
- Quick Installation Guide leaflet
The gallery below shows some pictures of the main unit. The unit is quite hefty at around 10 pounds without the hard drives installed. The dimensions of the main unit are 15.5cm x 25.3cm x 35.2cm. There are two internal 80mm fans which can be replaced by the user.
There are no HDD trays, but just plastic handles. The handles are also too flimsy for my liking. This means that 2.5" HDDs / SSDs are a no-go. I tried using a 3.5" adapter that is usually bundled with the SSDs, but the SATA connector on the mounted SSDs don't align up with the fixed SATA connector inside the Probox bay.
We managed to grab some photographs of the chips inside the unit. Three of them turned out to be JMicron bridge chips, as shown in the gallery below.
The main chips in the enclosure are:
JMS539: The JMicron JMS529 is a USB3.0 to SATAII 3Gbps bridge controller. It integrates a 60MIPS 8051 microcontroller along with 1 USB 3.0 PHY and 1 SATA PHY.
JMB321: The JMicron JMB321 is a single chip which integrates 6 SATAII 3 Gbps PHYs along with a host microprocessor. The firmware can configure it either as a 1-to-5 port SATAII port multiplier or 5-to-1 port SATAII selector. The Mediasonic Probox contains two of these JMB321 chips, using them in port multiplier mode. These two chips are used in cascaded configuration, with the output of the second one being routed either to the eSATA port or the JMS539 depending on the selected interface. As expected, simultaneous access of the SATA drives over both eSATA and USB 3.0 is not possible.
EM78P520: This microcontroller from Elan Microelectronics is used for overall housekeeping purposes.