When choosing an internal hard drive for your computer, the three main factors to keep in mind are compatibility, capacity and performance. Leading brands include Western Digital, Seagate and Toshiba.
Does bus type affect speed?
Internal hard disk drives (HDD) are frequently categorised according to type of interface, also known as bus system. This bus system is one of the major factors determining data transfer speed and reaction time - which are perhaps the two most important measurements of the performance of a product.
Internal Serial ATA (SATA) hard drives are extremely popular because they offer quicker data throughput and simpler cable routing than their predecessors, the IDE models. SATA II has a throughput rate of 3 gigabits per second, double that of SATA I drives. SATA III achieves a further doubling, reaching rates of 6 gigabits per second.
One such SATA III product is the aptly named Western Digital VelociRaptor WD1000. Testers at Techtree claimed it was the fastest mechanical model they had yet encountered. The Red SATA III 3TB (WD30EFRX) is a less expensive, yet solidly performing option, according to PC Advisor.
The majority of server HDDs are also equipped with a SATA bus. These server drives are suitable for use as central file storage, provide a variety of network functions and tend to be quieter and more energy efficient than average.
How do I know which HDDs perform well?Here a list of specifications to check in order to ensure that you purchase a top performing product:
- Speed, listed in rotations per minute (rpm), is another measurement overall performance. Average products hover around 7200 rpm, while exceptionally fast models can rotate at more than 15,000 rpm.
- Quick access times, under 8 milliseconds, and a large buffer are also signs of quality.
- A few products are equipped with NCQ (native command queuing) support, an extension of the SATA protocol. NCQ optimises the order in which read and write commands are executed, thereby improving throughput and reducing latency.
- Throughput refers to the amount of data that can be transferred from one location to another in a given amount of time.
- Latency is calculated from the rotation speed and seek speed of a device and indicates the time that it takes to load data from a sector. The lower the latency, the faster the product.
How much capacity do I need?
For the average user, 500 GB memory capacity is more than sufficient, especially considering the move towards cloud storage. However, anyone who records a lot of TV or video content to their hard drive, particularly in Full-HD or 4K resolution, should look for at least 2 TB.
According to Expert Reviews, a nice high capacity budget option is the Seagate Barracuda 1TB. Though certainly not the fastest internal model available, this tester said it performed well in small file transfer tests and was definitely a great value.
Form Factor: Which size fits?
Form factor is measured in inches. The 3.5-inch size is standard, fitting comfortably into most PC cases. This larger form also facilitates higher storage capacity.
However, smaller products, such as the popular 2.5-inch form, also offer advantages. They enable a higher rpm (rotations per minute), which can shorten latency, allowing faster loading and saving times. They are also less vulnerable to vibrations and shocks and consume less energy. At this time, 2.5-inch products with more than 2 TB storage are still quite rare, but if you do not require a high capacity product, then they are a viable option. Before purchasing a 2.5-inch model, make sure that your computer accommodates this form factor. You may need to use special brackets or trays to fit it into the larger 3.5-inch bay.
Regardless of form factor, remember that the HDD must be compatible with regards to height as well.