We transfer sets of 5GB of data to and from each drive multiple times. We use separate sets made up of large files and of small files. Testing is done using USB 3.0 (except for the Thunderbolt drive). We time the transfers, noting both the read and write speeds to measure the drive’s performance, averaging the speeds for a final figure.
We use PCs running Windows 7 and equipped with solid-state drive (SSD), except for Thunderbolt, which is tested using an Apple iMac with Fusion drive (combined SSD/HDD), which comes standard with a Thunderbolt port. This avoids possible bottlenecks that can occur using a slower mechanical hard drive. The test computer is rebooted between each test to ensure no speed benefit due to cached files during the write/read process. At the completion of all hard drive tests, the test computer is reimaged before testing a different hard drive.
Performance makes up 50% of the overall score.
* Assessed with the drives formatted as NTFS.
(A) Connected with Thunderbolt / USB 3.0 – Thunderbolt score used in the overall calculation.
(B) Connected with USB 3.0 / eSATA – USB 3.0 score used in Overall score calculation.
(C) Performance scores and real-time throughput measured with and without the Turbo Copy software installed.