Group test: NAS storage devices

Anthony Caruana
31 October, 2011
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Storage – we can never have enough. With desktop hard drives capable of up to 3TB of storage, iTunes libraries that grow by gigabytes per week and multiple computers that need to be backed up, the need for fast, reliable and extensible storage is growing.

Although USB and FireWire drives are cheap and easy to use, the problem is that they don’t offer extra protection for your data. If you’re storing important data on that drive and it fails then your data goes with it.

That’s where a NAS (Network Attached Storage) device comes to the fore. Think of a NAS as a purpose- built computer that is made for just one purpose – securely storing your data. The key technology that a NAS uses is RAID – the Redundant Array of Inexpensive Disks. With a RAID, a collection of disks is linked together to augment the functionality of each individual drive.

Let’s think about the simplest scenario – two drives working together. With two drives there are two options – the drives can either be joined together to create a single data volume.

If you start with two 1TB drives and configure them like this, you end up with 2TB of available space. In addition to the capacity, a configuration like this, designated as RAID0, offers faster performance than a single drive.

The problem with RAID0 is that if either of the drives fails, all the data from both drives is lost because of the way the data is written to the drive.

Those same two drives can also be configured in a different way. Instead of treating the two drives as one big volume, data can be mirrored between the two drives. So, if you start with two 1TB drives, you have 1TB of available space but all of the data is automatically written to both drives. If one drive fails, no data is lost. This configuration is called RAID1.

With two drives, things are relatively simple. However, the real value of a NAS comes when you use three or more drives. RAID5 takes the best of both worlds by allowing you to concatenate the capacity of multiple drives with data redundancy.

If three 1TB drives are placed in a RAID5 configuration, then the total available capacity is 2TB with data duplicated such that if one drive fails then nothing is lost. RAID6 takes this further by using two drives for redundancy.

With the six systems I tested here, I was disappointed to find that some required firmware updates and new configuration software. When you buy your new NAS, be sure to set some time and bandwidth aside for the setup.

Most NAS units are sold without any hard drives. The idea is that you choose the NAS hardware and then choose the hard drives that suit you. When choosing drives don’t just focus on price and capacity. While they’re important considerations, there are vast differences between entry-level consumer drives and high-performance ones with greater reliability.

In the past, I’ve tested NAS suites by conducting a series of file copies and operational activities such as watching movies and opening documents across the network.

This year, I’m using an Intel tool that mimics a variety of actions such as full-screen video playback, photo editing, office productivity and file and directory copying. The tool runs on a Windows machine but provides a set of repeatable benchmarks. I also carried out functional testing with a Mac.

Note that I haven’t reported raw numbers from the benchmark. As my test environment is unique, it’s doubtful that you’d be able to repeat the tests in exactly the same way. Rather, I’ve decided to report the results in relative terms, noting the faster and slower performers.

All of the equipment tested this year was connected via Gigabit LAN using new 2-metre CAT6 cables through an eight-port Gigabit router.


  • Drobo FS
  • QNAP TS-412
  • Synology DiskStation DS411+II
  • Seagate Black Armor
  • Netgear ReadyNAS Ultra4
  • D-Link DNS- 1200-05


2 people were compelled to have their say. We encourage you to do the same..

  1. h2omark says:

    I really appreciate these sort of reviews but am wondering why the DROBO didn’t get credit for being expandable while live. Perhaps, the other units also offer this feature? But if not I would have thought this to be a major plus. I use a DROBO S for HD video editing and really like the idea that I can not only replace dead drives but also expand the RAID capacity live. cheers

  2. Pete says:

    I was really looking forward to this review, as I’m looking to buy one of these products. However, I’m a little puzzled as to the review of the Drobo. The Drobo FS can be used for time machine backups, and for the iTunes library.

    It appears that this review is either biased, or just not as well researched as I’ve come to enjoy from my favourite magazine.

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