External Hard Drives: Which to Use?
External hard drives are used for everything from personal data backup to professional video editing. The work load and performance requirements determine what drive is appropriate for a given usage. This applies to a PC, a MacBook, any other computer that uses an external hard drive..
An external drive acts as an expansion of your computer system, but brings with it the added advantage of portability. Since little or no installation is required beyond plugging in a cable, an external drive provides an instant system upgrade. Some external drives allow hot plugging (attaching the drive while the system is powered up).
USB, FireWire, eSATA, Thunderbolt, and Ethernet are popular interfaces for external drives. Your system may support more than one type. Also note there are variations within the types (USB 2.0, USB 3.0, Firewire 400, Firewire 800).
Considerations when choosing a drive
Is the drive used for backup only?
The main requirement for personal backup is reliability. The speed of a backup drive becomes more of an issue when it is used for a high demand purpose or it is handling large amounts of data. The higher the performance, the less time it takes to do a backup or retrieve files. So the first thing to do is to determine the use of the drive.
Is the drive supporting real time events such as video or audio recording?
Recording and editing audio or video requires large amounts of data to flow in a more continuous manner. The speed of the drive, along with the buffer (cache), are two of the factors that can affect data transfer performance. When editing audio or video the drive's performance can also impact screen redraw quickness.
Drives designed for heavy audio and video usage are sometimes referred to as "AV drives." A rule of thumb, for rotating drives, is to use only 7200rpm or higher drives for such high demand uses. With solid state drives, some are suitable than others for high demand, high performance usage. Check with the specific hardware or software maker for compatibility with a high demand setup such audio editing, video editing, or mass backup.
What type of external drives are supported by the computer system?
Are you using a Mac or PC? Does the computer have the correct interface connections for the drive? Some hardware and software is designed to work only with certain interfaces. Some drives (mostly smaller portable models) are powered by the buss connection while others use a separate power supply. If bus powered, will your connection power the drive? Do you have multiple devices running off the ports? Are you using a hub? An optional power supply may be required for some drives or configurations.
How important is portability?
Nowadays some small drives are capable of providing high performance. However, a full size drive may still win out for shear power and durability. Consider opting for the highest possible performance for a stationary system, then add a portable drive for travel. Ideally the portable drive should still provide adequate performance to be used as the main drive with some limitations.
How much critical work will be done with the drive?
Don’t take chances with and inferior drive when it is used to create (or store) hours and hours of important work. This is especially true in a production environment. A drive used for video editing or shared network takes a lot of abuse. The internal drive mechanism (within the enclosure) is not the only issue. An enclosure with poorly designed interface circuitry or power supply can leave you wishing you bought a better drive. In a worst-case scenario a faulty power supply could possibly damage the internal drive. Regardless of the quality of your main drive, always keep multiple copies of crucial files on separate drives. When a drive goes bad it can be a minor hassle or a major disaster according how well you maintain file backups.
The most common and generally the least expensive interface type. USB (Universal Serial Bus) is found on just about every brand of modern computer. USB is used for all sorts of devices including printers, cameras, and flash drives. For many applications, USB 2.0 (even 1.0 or 1.1) is fast enough. USB 3.0 has become quite common and is theoretically up to 10 times faster than USB 2.0. USB 3.0 has a potential 5 Gbps data rate, but expect more in the 3 Gbps range.
Developed and popularized by Apple, FireWire is fast and stable. Popular software and hardware systems have made FireWire somewhat of a standard for audio and video. FireWire 400 and FireWire 800 are capable of speeds up to 400 Mbps and 800 Mbps respectively.
eSATA (external SATA)
An interface based on the once internal only SATA technology. The eSATA format is capable of extremely fast speeds since the data path does not require a conversion of the transfer data to the USB or FireWire protocol. An eSATA port can be added to some computers or to laptops with expansion card slots.
Developed by Intel, Thunderbolt™ technology has now entered the mainstream and is a standard feature of Apple computers. Offering bi-directional transfer rates of 10 Gbps, Thunderbolt is an especially welcome advancement for demanding uses like video.
Thunderbolt 2 now extends the speed to 20 Gbps.
Ethernet is less common in smaller external drives, but more likely to be found on drives, and drive arrays, intended for use in a network. Ethernet connections are often labeled 10/100 or 10/100/1000 with the 1000 referring to a 1Gbit/sec transfer rate.
Everything USB: SuperSpeed USB 3.0 FAQ
Apple: Firewire: Frequently Asked Questions
Intel: Thunderbolt™ Technology
Thunderbolt is a trademark of Intel Corporation in the U.S. and/or other countries.