How we test: Hard drives and solid state drives
Media--including your photos, music, home movies, and television programs--is going digital. This means that you'll require computer storage space: hard drives and solid-state drives. When it's time to upgrade or add more storage in order to accommodate your growing media collection, you need to consider more than just gigabytes. Depending on the applications, it's usually not enough to consider just the storage capacity; you must also consider performance. Not all drives are created equal, and you'll really feel the difference when you're waiting for those huge files to open. In order to deliver relevant performance evaluations of hard drives, CNET Labs puts drives through their paces with the real-world tasks of reading and writing files.
Test environment
Hard drives are tested using a desktop system with an Intel Core i5 2300 2.8Ghz Processor, 8GB of OCZ DDR3 RAM, an Nvidia Geforce GT 200 video card, a 240GB OCZ Vertex 3 solid-state drive , and Windows 7 Ultimate SP1 64-bit. Internal SATA hard drives are connected to an available SATA 3 (6Gbps) channel on the test bed motherboard, which is an Asus P8P67 WS Revolution. External SATA hard drives are connected to an available peripheral port (eSATA, FireWire, USB 2.0, and USB 3.0). All tested hard drives are formatted with a single NTFS partition at the maximum supported storage capacity of the drive.
Transfer-speed tests (external drives and internal drives)
The read and write transfer-speed tests are done using a folder containing approximately 50GB of data that contains DOC, XLS, JPEG, GIF, HTML, TXT, MP3, AVI, and application installation files, ranging in size from 18KB to 698MB. We use a custom utility designed by CNET Labs to simulate the drag-and-drop mode of file copying in Windows Explorer. The custom utility automatically times the file transfer tests, reporting how long it takes to complete the transfer in minutes and seconds as well as in megabytes per seconds.
The write test is conducted by timing how long it takes to copy the 50GB folder from the test bed's permanent hard drive to the drive being tested. The read test (external drives only) is conducted by timing how long it takes to copy the 50GB folder from the drive being tested to the test bed's permanent hard drive. All files copied to the drive being tested stay on the drive and are not deleted between test runs. This allows the drive to increasingly fill up with data as testing continues. All tests are repeated a minimum of three times. Each reported score represents an average of three scores that are within 5 percent of each other; iterations that vary by more than 5 percent are thrown out. All scores are reported in minutes and seconds, so lower scores indicate faster performance.
General performance tests (internal drives only)
We use the tested drive as the main drive of the test bed and perform a variety of simulated workloads with mainstream software suites, including Office (Word, Excel, PowerPoint), iTunes, QuickTime, to gauge the impact of the tested drive on the whole system's performance. We also time the system's boot and shutdown times when the tested drive is used as its main drive.
We also do another set of transfer-speed tests from within the drive itself (from one folder to another) to gauge the drive's performance when it has to handle reading and writing at the same time.
