How to choose the right HDD for my Synology NAS

With myriad hard drive classes and models available, selecting the right hard drive for a Synology NAS might feel like a daunting task. This article will explain some of the major differences between various hard drive classes available on the market, as well as what considerations are needed when selecting the right hard drive for Synology NAS.

Currently there are four major hard drive classes on the market, each designed for specific applications, workloads, MTBF (Mean Time Between Failures), and POH (Power-On-Hours). Basically, all hard drive classes can be used with Synology NAS, but we recommend choosing the right drive class to fit your needs:

  1. Desktop drives: Desktop drives are designed for desktop or notebook computers where usually a single drive is installed. Most desktop drives are more affordable, but seldom come with vibration protection, making them more vulnerable in multi-drive RAID environments where vibration from other drives and the system chassis can affect both drive health and system performance. When installed in NAS systems, desktop drives are suitable for situations where data is not often accessed, such as serving a small group of users who occasionally save or access documents on the drive, or as a backup storage destination which only requires a few hours of activity each day.
  2. Enterprise drives: Enterprise drives are often manufactured using more advanced technology or superior components to provide better performance, POH, MTBF, vibration protection, and error correction. When installed in NAS systems, enterprise drives are suitable for environments that require high data availability and consistent throughput even when moving large amounts of data. This means enterprise drives are more appropriate for businesses with numerous employees accessing files simultaneously, database servers, or virtual storage systems.
  3. NAS drives: For users who find desktop drives not durable enough, and enterprise drives too expensive to afford, NAS drives provide an alternative that is optimized for NAS usage. They often feature better durability, balanced performance, and power consumption when compared to desktop drives.

    Note:

    Some NAS drives lack vibration sensors and may not be suitable for multi-bay and rack systems. Please check with manufacturers for details regarding hard drive specifications before purchasing.

  4. Surveillance drives: To accommodate the 24/7 demands of long video recordings, surveillance drives are optimized for sequential write operations, but offer lower random access performance.

    Note:

    • Some surveillance drives lack vibration sensors and may not be suitable for multi-bay and rack systems. Please check with manufacturers for details regarding hard drive specifications before purchasing.
    • If the workload exceeds the maximum capability of surveillance drives, we recommend using enterprse drives.

Term Explanation

  • Mean Time Between Failures (MTBF): MTBF is a statistic used by manufacturers to state the reliability of hard drives. Often the higher the MTBF, the lower chance of failure. Note that there is no manufacturer of any hard drive that can absolutely guarantee zero failures.
  • Power-On-Hours (POH): POH is the length of time, in hours, that electrical power is applied to a device. For hard drives, two categories are usually used:
    • 8/5: eight hours a day, 5 days per week.
    • 24/7: 24 hours a day, for every single day in the year.
  • Workload: user's data transfer rate (terabytes per annum) with the drives.

Further Reading