Any device connected to a Gigabit LAN will have maximum read and write speeds of 125MB/sec. However, just as the controller chip on an SSD has a huge effect on the drive's speed, the same is also true for NAS boxes. As they’ll be used for storing lots of tiny files, as well as large video files, we used two 5GB folders (one full of small files, and the other packed with large video files), in order to gauge the flexibility of each box.
Our test involves writing to each NAS box separately from our PC into a shared folder created on the NAS, and then reading from them. The small file folder was filled with 10,000 files that included photos, Word documents and short videos, while the large file folder comprised three 1.7GB videos.
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We now use SSDs at either end of the testing to make sure the storage devices aren't the bottlenecks. Of course, real-world performance will vary depending on hard disk speed but we're offering maximum throughput figures. We recorded the time it took to transfer each folder in seconds, and used this result to work out the average transfer rate. You can see the speed test results in the graphs below.
Once a NAS box is up and running, we then also try out all of the features, such as shared folders, iTunes servers, iSCSI and Bit-Torrent clients, in order to see how easy they are to set up and use on a regular basis. In addition, we also take noise and hard drive temperature into consideration, as well as the build quality.
We've removed many of the older results from our graphs as many models are now end of life or have far newer operating systems that we're unable to test as we no longer have the products in our possession. In the interest of fairness, we'll only be including recently-reviewed products in the graphs.