Performance, Pricing and Conclusion


To simulate a typical user upgrade from the 4-bay Drobo, I shut down our older unit (still with a set of 4x 4TB WD Reds installed), moved the pack of disks to the 5C, fired it up, and the array appeared as if I hadn't even switched the devices at all!

  • Sequential performance of this 4-disc pack:
    • 226 MB/s read and 204 MB/s write.
  • I then shifted to dual redundancy mode:
    • 225 MB/s read and 178 MB/s write.
  • I then dropped back down to single redundancy and added a 6TB Red:
    • 232 MB/s read and 216 MB/s write.
  • Shifted to dual redundancy on the 5-disc pack:
    • 220 MB/s read and 198 MB/s write.
  • I then removed the mixed capacity pack and shifted to 5x 8TB WD Red:
    • 226 MB/s read and 215 MB/s write.
  • Shifted to dual redundancy:
    • 229 MB/s read and 193 MB/s write.

ATTO run of the array (in dual redundancy mode):

Keep in mind that without a hot data cache present (as in the more expensive 5D and 5N), the 5C's strength comes in its straight line speed. Heavy random writes will not fare well here, as the primary purpose is the bulk storage of larger files and media. Do your edits on your internal drive prior to exporting / archiving to the Drobo 5C and you'll have a good experience.

As with the 3rd gen Drobo, we occasionally caught it shuffling metadata during some of the writes. This is not a normal condition unless you are particularly hard on your array:

Overall, performance was nearly identical to the 4-bay unit the 5C replaces, with one notable exception. Migration and rebuild times appeared to take nearly twice as long on this new unit. This may be something that can be corrected with a firmware update in the future, or it may be a limitation imposed by the new larger 64TB volume size. Since rebuilds occur in the background and data remains accessible, I don't consider this a significant issue at this time, but it is something to keep in mind.


The Drobo 5C is available today at a list price of $349. This is the same MSRP as the 4-bay model this one replaces (which almost immediately sold at $267), so don’t be surprised if this new 5C drops in price a bit after launch. There is also a $50 discount to Drobo gen2 or gen3 owners until 11 OCT 2016 if purchased from the Drobo Store.



  • Speed. Not much faster than the 4-bay Gen-3 part it replaces, but still reasonably quick.
  • Superior out of box experience. Setup and configuration is dead simple.
  • The same BeyondRAID technology that we could not break 7 years ago.
    • Internal battery backup provides further protection of the array.
    • New 64TB volume size offers future-proofing and simplifies setup (no need for multiple volumes with large disks)
  • High quality stamped steel construction.


  • Occasional background activities can negatively impact write speeds.
  • 64TB volume size appears to extend rebuild and migration times considerably.

Building on the winning low-cost formula of the third-gen 4-bay Drobo, the Drobo 5C brings back the extra bay seen in the 5D and 5N models, but at nearly half the cost. While the 5C offers USB Type-C connectivity, Drobo opted to go with USB 3.0 link. The 5Gbps link is not a bottleneck since the 5C is chipset / HDD speed limited to ~250 MB/s. Realizing that not all users have a Type-C connector on their system, a Type-C to Type-A cable is included. Those rare few with *only* Type-C connectivity will have to pick up an extra cable.

Speeds were good overall, with the 5C offering similar performance to the superseded 4-bay Drobo. 64TB volume support is a welcome addition, but comes at a cost of longer rebuild and migration times. BeyondRAID keeps all data available regardless of background activity, so the only real side-effect will be reduced write speeds during these periods.

The Drobo 5C is the best game in town when it comes to robust direct-attached storage.

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