Selecting Drives for High Performance With Drobo DAS

Drobo direct attached solutions (DAS), Drobo 5D3, Drobo 5D and Drobo 5C, are powerful devices for optimizing and storing your media. Utilizing cutting-edge Thunderbolt™ 2 and 3 and USB Type, C technology, they provide blazing-fast access to your media. However, to receive the maximum performance with Drobo, selecting the right drives is crucial. Below, we share three recommendations for selecting drives for your Drobo DAS.

1) Selecting Drives

The Drobo can be mixed and matched with different size and brand hard drives, creating a simple solution for expanding your data. However, to achieve maximum performance we recommend selecting desktop performance drives with a 7200RPM speed. The RPM, or Revolutions Per Minute, is the frequency and rotation of the drive. The faster a disk can spin, the faster it can read and write data. As Drobo will run on the slowest drive speed in the disk pack, we recommend inserting the same brand and type of drive into each Drobo bay. For example, inserting five Seagate BarraCuda Pros will accelerate the speed.

Desktop vs. NAS drives
Desktop drives are typically faster than NAS drives because they spin faster. Most NAS drives spin at either 5400RPM or 5900RPM, whereas desktop drives spin at 7200RPM. Some of the higher end NAS drives spin at 7200RPM, but even those are slower than a quality desktop performance drive. The difference between a 7200RPM NAS drive and 7200RPM Desktop drive is usually the platter density. The NAS drives have less platters, each with a higher density, whereas the desktop performance drives tend to have more platters at a lower density. This allows the drive heads to settle on the track quicker.

Desktop vs. SSDs
The Drobo is compatible with solid state drives (SSD), which are a form of flash memory. Unlike hard disk drives (HDD), they do not spin, allowing them to operate at faster speeds. To use SSDs with Drobo, you will need to place each SSD in a carrier bay, as well as use all SSDs for each Drobo bay. This is due to the Drobo performing at the slowest drive speed in the pack. However, by selecting a performance desktop drive (HDD), you will receive almost the speeds of SDDs and save additional costs.

2) Number of Drives

The Drobo can expand up to 64TB, depending on the drive capacities. To protect your data against drive failures, the Drobo automatically allocates a portion of your drive space for protection. At least two drives are needed to enable the automatic single disk redundancy, meaning the data is protected against one drive failure. To enable dual disk redundancy, at least three drives are needed for protection against two simultaneous drive failures. To simply calculate your capacity, please see the Drobo Capacity Calculator.

The number of drives in the Drobo directly impacts the performance you will receive. For write speeds, having three to five disks in the Drobo, increases the disk transfers up to twice as fast. Drobo will read and write to all the drives simultaneously, so the more drives there are, the higher aggregate disk throughput Drobo will see. For example, if the Drobo is writing 10MB of user data and it has 3 disks, Drobo will write 5MB to each of two disks and then a further 5MB of redundancy data to the third disk. Meaning, Drobo waits for each disk to accept 5MB of data before the 10MB of user data write can be completed.

3) Additional Performance Boost

Access your files up to 30% faster by inserting an mSATA card into the built-in Accelerator Bay, located on the bottom of the Drobo. An mSATA card is a form of SSD, which caches recently used files. The bigger the capacity of the card, the more it can store. For more information and recommendations please see our mSATA blog.

Recommended for Drobo DAS Performance: Seagate BarraCuda Pro With Data Recovery (Included with 7200RPM)


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