Hard Drive Introduction: Form Factors, Spindle Speeds, and Interfaces

            If you’re just introducing yourself to the world of computer storage options, you’ll be coming across thousands of options from dozens of manufacturers. Familiarizing yourself as well as possible with the variety of options on the market is the best way to ensure that you choose the right hard drive for your specific needs. Here, I will be aiming to arm you with all the introductory knowledge for your future hard drive purchases. The information covered here will include a short introduction on hard drive form factors, spindle speeds, interfaces, and other general information. Keep reading below for more information.

Hard Drive Form Factor

The form factor of your hard drive refers to its standardized dimensions. The form factor is the largest determining factor in selecting a hard drive for a specific system. Over the years, form factors have progressed to become smaller. Whereas the first hard drives were the size of refrigerators and had capacity for a few megabytes of data, today’s hard drives have been micronized to the point that terabytes of storage can fit on a very small form factor. In general, however, hard drives have been standardized into a few form factors. 3.5 is the standard for desktop drives, and offer the highest availability in capacity and spindle speed (this is also the standard form of server hard drives). 2.5 hard drives are typically intended for use in notebooks, though can be mounted in desktops as well. 1.8 drives aren’t as common, but are usually intended for ultra-thin or ultraportable computer solutions.

Hard Drive Spindle Speeds

One important factor to pay attention to in any potential purchase is the hard drive’s spindle speed. A hard drive works by using an actuator arm and a magnetically receptive platter to both write data (store) and read data (retrieve). The data is stored on an actual physical location on a platter, and the actuator arm (with a magnetically receptive head) must seek to this location before the data can be read. Thus, the speed of the drive’s performance is determined in no small part by the rate at which this data can be located. A higher spindle speed allows the data to be read at a faster rate as the platter rotates more quickly. Spindle speeds range from a relatively slow 5,400 RPM into the 7,200 range (standard for most budget-efficient drives), and the higher end 10K and 15K range. Solid state drives work with a flash storage alternative, and thus can cut out the mechanical operating principal. Such drives offer much higher speeds.

Hard Drive Interfaces

 
Today’s standard hard drive interfaces with your motherboard via a SATA connection. My own system uses a 496798-001 SATA cable to interface, though SAS drives are also compatible with SATA connections. Other interfaces include older IDE drives and SCSI. However, SATA I, II, and III have proven to be the most advantageous interfacing option. Hopefully I’ve provided you with a solid introduction to the basics of hard drives. Thanks for reading!