Why My Drobo 5C DAS Storage is So Slow?

Drobo 5C - Why My Drobo 5C DAS Storage is So Slow?

Drobo 5C comes with a state-of-art USB Type-C interface that is compatible with both USB 3.0 and USB 2.0.  So the data transfer speed should be pretty fast when connected to my computer via a USB 3.0 port. But it’s crawling like USB 2.0 when I connected it using the USB Type-C to USB 3.0 A cable that comes with the box and ran a quick test.

Drobo on USB 218 complete 2017 09 11 09 40 19 - Why My Drobo 5C DAS Storage is So Slow?

And I use a tool called USB Device Tree Viewer to check out, it’s indeed connected as a USB 2.0 device.

USB Device Tree Viewer V3.1.2 2017 09 11 09 39 24 600x365 - Why My Drobo 5C DAS Storage is So Slow?

So WTF? There is no way I can use a 10TB external storage with a USB 2.0 connector in a real life. I don’t believe the brand like Drobo will design such a bad product like this. There must be something wrong in the middle.

Turns out, it’s the USB-Type C cable that’s causing the problem. Just because it’s a USB-Type C cable that is designed to be plugged in regardless of the side doesn’t mean that it works the same way. Yes, sounds ridiculous but when I flipped the cable around and plugged it in, the Drobo box is suddenly connected as a USB 3.0 device.

USB Device Tree Viewer V3.1.2 2017 09 11 09 38 44 600x365 - Why My Drobo 5C DAS Storage is So Slow?

And it transfers just like a USB 3.0 device as well. Believe it or not, that’s probably one of many reasons why Microsoft hates USB-C.

Drobo 5c on USB 3 - Why My Drobo 5C DAS Storage is So Slow?

That looks much satisfying.

As another side note, I also ordered a USB Type-C to USB Type-C cable and was hoping to use it to connect the Drobo box through a native USB Type-C connection. But I didn’t pay attention to the product description and ordered one that is only for USB 2.0. Therefore, no matter which side I use to connect, it’s always connected as USB 2.0. Hope you just don’t make the same mistake I made.

3 thoughts on “Why My Drobo 5C DAS Storage is So Slow?

  1. Thanks a lot for this post. I was having exactly the same problem. I even had a “double–sided” USB–C cable so I thought there was no possibility that was the problem but USB Device Tree Viewer showed even that was connecting at 2.0. I tracked down a better cable, verified with USB Device Tree Viewer and my read / write speeds went from 30 MB / second to 135.

  2. Thank you so much!

    I have finally sat down tonight to try to get to the bottom of this.

    My Drobo 5C was always slow on my old PC, and I’ve just put it on a new one with a Super Speed (SS marked) USB port.

    I was still only getting 40MB/sec so went hunting for information and found your page. Following the instructions it was indeed only ‘seen’ as a USB 2.0 device by the host.

    I shut the Drobo 5C down, flipped the connector in the back of the Drobo the other way up, powered back up and am now getting 220MB/sec!

    I cannot believe this isn’t written in 10 foot high letters somewhere in the Drobo guides and the cabel should have a ‘this way up’ marking. It is ridiculous!

    Thanks again so much!

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