Power Consumption and Miscellaneous Factors:

In the typical usage scenario, the Probox will be used with 3.5" hard disk drives. A majority of the end users plan on using a DAS unit to store multimedia files. Typical access to these types of files involves sequential reads and writes. In order to evaluate performance and power consumption under these typical usage conditions, we used 7200rpm 1TB HDDs and ran 128K sequential access tests with high queue depth using IOMeter. The results are presented below. As seen in the previous section, USB 3.0 performance seems to plateau, while eSATA seems to be able to deliver much better performance. eSATA is unusable for configurations with more than two drives.

Despite being advertised as being able to provide 5 Gbps of bandwidth, the USB 3.0 port is obviously held back by the 3 Gbps limit of the SATA side of the bridge chip. In practice, both the read and the write bandwidth seems to be limited to around 180 MBps. On the other hand, eSATA seems to be able to reach as high as 240 MBps and probably has the ability to even perform a bit better with a suitable eSATA port. We may update the piece after the receipt of a suitable eSATA add-on card.

The table below presents the power consumed at the wall (as measured using a Watts Up? Pro meter) under various conditions. In the table below, the access column refers to 128K sequential reads and writes with a queue depth of 64. The average of the numbers obtained for reads and writes is presented. Between USB 3.0 and eSATA in the 1 and 2 disk configurations, we found that the power numbers were different by only a few tenths of a watt. Therefore, all the numbers presented below are for access through the USB interface

Mediasonic Probox 8-bay Single Mode DAS Enclosure Power Consumption
 
Turned Off 0.6 W
No Disks / Min. Fan Speed 12 W
No Disks / Mid. Fan Speed 13 W
No Disks / Max. Fan Speed 15.9 W
 
No. of Disks Idle Access (Min. Fan Speed)
1 17 W 19.7 W
2 22.7 W 26.8 W
3 28.1 W 32.8 W
4 33.5 W 39.7 W
5 39.4 W 46.5 W
6 44.9 W 52.5 W
7 50.1 W 59.0 W
8 55.6 W 65.1 W

The two fans in the unit can be put under manual or auto control. The auto control is enabled by thermal sensors and the feature works well in practice. There are three fan settings. In such units, the fans are the most likely components to fail first. Thankfully, they are quite easy to replace and Mediasonic doesn't void the warranty when users replace the fans themselves.

The unit also has sync settings which enable it to power on and off in tandem with the computer's power state. The hard disks are also allowed to go to sleep as per the drive's firmware settings (the duration can be modified for most disks using the smartctl utility).

Some users have reported problems with the USB 3.0 connection having issues, but we didn't encounter any issues in our stress testing. We can only conclude that the USB 3.0 ports on the H77 chipset / Intel's USB 3.0 drivers don't have any issues in interacting with the JMicron USB 3.0 to SATA bridge.

Performance Benchmarks Final Words
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  • repoman27 - Saturday, August 04, 2012 - link

    When you guys review USB 3.0 gear, you really need to address whose drivers you are using on the testbed and whether the device is operating in BOT, BOT with oversized payloads, or UASP mode.

    USB without UASP doesn't support queuing, so increasing the queue depths won't make much difference in your results. I'm guessing you were operating in BOT mode with default payload size and that is why eSATA was able to outperform USB 3.0. (And looking at the specs for the JMS539, I don't see any mention of UASP support.)
    Reply
  • repoman27 - Saturday, August 04, 2012 - link

    Also, most reviews don't mention specifically which USB 3.0 controller is being used, although in this case the board in question only has the integrated Intel controller.

    In the interview with JJ from Asus, he mentioned that memory bandwidth had an impact on Intel integrated USB 3.0 performance. I'm not sure if you have ever seen this borne out in actual testing, but I did note that your testbed was only running DDR3 1333.
    Reply
  • ganeshts - Saturday, August 04, 2012 - link

    I should have specified this in this review too. But, over here [ http://www.anandtech.com/show/6014/startechcom-usb... ], using the same testbed, we found that UASP is not supported by the Intel PCH's USB3 ports. Only ASMedia supports it right now.

    Further, the JMicron USB3 - SATA bridge supports only BOT specifications, as you have indicated. So, UASP enabled testbeds would probably have not made any difference.
    Reply
  • repoman27 - Monday, August 06, 2012 - link

    Supposedly some Asus boards will support UASP on the USB 3.0 ports provided by the Intel PCH using the Asus drivers. [ http://www.tomshardware.com/reviews/usb-3-uas-turb... ] I believe UASP is also supported for the integrated Intel USB 3.0 controller under Windows 8 and Mac OS X.

    Even using BOT though, increasing the maximum transfer length can have a considerable impact on sequential performance. So I wonder if your numbers are at the upper end for the Probox, or if it still had another 20-25% to go under USB 3.0 given the right conditions.

    At this juncture, directly comparing benchmarks of USB 3.0 storage solutions is a total crap-shoot because there are so many variables and almost every site reviewing gear glosses over a fair number of the details.
    Reply
  • yyrkoon - Saturday, August 04, 2012 - link

    Ok I have not finished reading the article yet, but I *have* to say something.

    What do you mean there were no such issues with USB 3.0 in relation to your eSATA port multiplication issues ? This makes you the reviewer sound clueless. PM support always depended on very few specific Intel, Jmicron, and now I suppose Marvell chip sets to work..

    Just to clarify This is a failing in your motherboard(s) or discrete eSATA controller cards. Not the fault of the enclosure. .
    Reply
  • yyrkoon - Saturday, August 04, 2012 - link

    Sorry, I said Intel Chip sets, where I meant Silicon image chip sets. Silicon image 3114, and 3132 chip sets where provided on a very few motherboards back in the Core2Duo days. A few generations of motherboards before ABIT dropped out of the motherboard business.

    At any rate. Addonics has made/sold PM capable controller cards for years.
    Reply
  • ganeshts - Saturday, August 04, 2012 - link

    When I specificed 'USB 3.0 had no such issues', I meant that I was able to access all the drives in the enclosure without experiencing BSODs unlike the eSATA case. I think all our readers know enough to understand that USB 3.0 has no port multiplication feature :)

    Yes, I have mentioned that it is a problem of the eSATA ports of most systems out there, and I have also mentioned that Mediasonic should have bundled one of those eSATA cards capable of seeing 8 drives through the eSATA port. Otherwise, they end up with customer service threads like the one here : http://forum.mediasonic.ca/viewtopic.php?f=27&...
    Reply
  • yyrkoon - Saturday, August 04, 2012 - link

    "I think all our readers know enough to understand that USB 3.0 has no port multiplication feature :)"

    This is not what I was saying. My point was that technically, the eSATA issues you had, was all the fault of the hardware you used to connect to the tower. E.G. your motherboards. But it looked like you were saying that Mediasonic's eSATA implementation was bad. Which is very likely not the case. No use in lamenting over a controller card not being included. As when you purchase such a device. You had better know what you're getting into, and you should already know this.

    This is the problem with multiple drive eSATA technology. It is complicated, convoluted, and in general half baked from conception compared to other technologies. However, do not get me wrong, I personally was very interested in eSATA PM technology from the start 5+ years ago. From specification to end user product however. It rarely pans out very well. Unless you spend boatloads of cash. Where you have to ask yourself "why eSATA instead of SAS, or ( insert other external drive technology here )..

    With everything above said. I think that manufactures should just leave eSATA out of the mix, and pass the savings onto us. the consumers. USB3 is not great, but it is good enough and flexible. Thunderbolt I think could be a great option too. If someone were to make say a 4 SATA drive to Thunderbolt bridge device.

    As for the "bad customer service thread thing". I think you would find that with many, many eSATA implementations. Even the single drives ones. Have many issues. Where drives suddenly drop offline, experience terrible speeds. ETC,ETC. This is why yours truly completely opted out of eSATA entirely, and went with USB3.
    Reply
  • tuxRoller - Sunday, August 05, 2012 - link

    I interpreted the author as saying that the problem lay in the side of the motherboard companies making it too difficult to determine if their esata chip is multi-port aware. Reply
  • yyrkoon - Sunday, August 05, 2012 - link

    Yeah I got that. However, I like you recognized the authors um . . . obvious inexperience with the given technology.

    You *do not* go out and test equipment like this without having the proper support hardware as well. Complaining, whining, or otherwise crying about hardware not included is simply inexcusable.

    The things you, and I both know. Is that port multiplier technology does not work without the proper controller chip set period. Sometimes, with the right equipment, you *can* perhaps access RAID arrays previously setup by a system that did have the right controller chip set. However, that array has to have previously been setup with an appropriate SI controller( or equivalent ). It is miraculous that the reviewer was even able to see even a single drive. Let alone all drives one at a time. If I understood what was written correctly. Granted, a few Addonics products can / do this for the user through hardware switches. . .

    You know this. I know this. The difference between you and I however. Is that you have actual hands on experience with the hardware / technology. I on the other hand have no hands on experience. Just a lot of reading over the past several years ( since the specification was released ). As eSATA PM technology has always been of interest to me.

    The point being here. Is that if someone can have knowledge of something without laying hands on actual hardware. There is no reason why a reviewer ( hopefully someone with some expertise ) should not as well.

    @ Ganesh

    Take this as a learning experience Ganesh. Not a slight. With a little more preparation, research, then perhaps willingness to work with the given hardware. Us readers could have learned more, and we could have had a proper review of the given product. As it stand, personally I feel like your review is incomplete.
    Reply

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