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
  • Screwdriver
  • 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.



Introduction and Testbed Setup Performance Benchmarks
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  • cdbob - Monday, August 6, 2012 - link

    I built an NAS using the G530 and it works great. The best value for money you could get.
  • Deptacon - Tuesday, August 7, 2012 - link

    I have 16TB's of data spread across 8 drives..... this is plug and play from one machine, and frees up room in my machine....thats what these are for.
  • PommieB - Saturday, August 4, 2012 - link

    Bit disappointed in this review, especially the lack of knowledge about eSata and Port Multiplication, I've run eSata and multiple enclosures for at least 5 or so years, I've had little or no problems using them, I'm running this particular enclosure connected to a Asus M70 laptop with no problems at all, it runs via a PM aware Addonics eSata expresscard without problems, the expresscard has a SIL3132 chip, something I checked prior to buying this particular enclosure, never had blue screens with esata, but then I do the research beforehand, something the reviewer should have done in the first place, I don't have USB3.0, so far I haven't needed it.

    All I can say, for the price these enclosures work well and so does the eSata, that's if you understand PM and know what your doing, same goes for eSata.
  • ganeshts - Saturday, August 4, 2012 - link

    The introduction section mentioned that a PM link needs to be used. However, not many users realize that their board's eSATA port most probably doesn't support port multipliers.

    One of the aims of this review was to educate the readers about this issue. Just trying to make sure that readers have a proper PM supporting eSATA port before expecting eSATA to work in this unit.
  • yyrkoon - Sunday, August 5, 2012 - link

    Well then. Educate the readers who need it. But not at the expense of a product you are reviewing.

    I completely agree with the OP here on this thread. Which is why you saw my post on the first page.
  • overanalysis - Thursday, August 9, 2012 - link


    are you saying the expresscard using the sil3132 will add the multiport function to your labtop even if the chip set on mobo doesn't have it. I have xps 1640 w/ ICH9 chipset that doesn't support port mulitiplier. I have a 4 bay probox that does not have PM controller in it. I was going to going to use a usb 3 espresscard but would prefer to use the esata if I could.
  • PureHazard - Saturday, August 11, 2012 - link

    Yes, he's saying exactly that. The Sil3132 will have a port multiplier enabling you to see up to 8 hard drives via eSATA.
  • tuxRoller - Sunday, August 5, 2012 - link

    I'd be curious how a linux distro (fedora, say) handles this setup.
  • yyrkoon - Sunday, August 5, 2012 - link

    Heh, I'm thinking you'd have better luck asking for openSolaris advice on this site . ..

    but freenode.irc -> ##fedora perhaps ?
  • tuxRoller - Sunday, August 5, 2012 - link

    I suppose you are referring to their zfs coverage?
    Fedora, or something like RHEL storage, should be able to handle this easily using lvm2 + whatever fs you like.
    Mainly, though, I'm curious about the usb3 performance comparison. Linux has had usb 3 support for ages, and driver quality for windows can be quite variable for usb3.

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