Portable & USB Hard Drives

An external hard disk drive is a standalone storage device that provides additional space for your data. You can use it to backup important files from your computer's internal hard drive and to transfer files between computers. It has a larger storage capacity than other external storage devices, like USB drives and memory cards.

Portable vs. Desktop External Hard Drives

A portable external storage drive is smaller and lighter than a desktop model. It's a compact unit that houses a 2.5-inch hard drive in a protective enclosure. Desktop external hard disks have bigger housings, and usually use larger 3.5-inch hard drives. You can turn the internal hard disk in your old laptop (2.5-inch) or desktop PC (3.5-inch) into an external storage unit with the right hard drive enclosure.

Another difference between desktop and portable external hard drives is their power sources. Portable units are bus-powered. This means that they draw power with the same USB cable used for transferring data. Desktop units have separate AC adapters and draw more power. Hard drive arrays are another class of external storage devices. These have two or more drive bays for 2.5-inch or 3.5-inch hard disks. They serve as network-attached servers and support RAID levels that help them prioritize data redundancy, transfer speed, and storage capacity.

What's the Difference Between SSD and HDD?

A USB external hard drive can store files on a solid-state drive or a hard disk drive. While HDDs record data on spinning platters, SSDs use flash memory chips. With no moving parts, SSDs are faster and more durable. They’re also quieter and use less power. However, HDDs are more affordable and available in higher capacities.

Some brands offer SSDs in multiple form factors. For example, you can find 2.5-inch (direct replacement for laptop HDDs), M.2, and PCIe solid state drives in the HP hard drive line. Note that you need a 2.5-inch SSD and a 2.5-inch drive enclosure to build a SATA external hard drive. SATA, or Serial ATA, is a high-speed bus interface for connecting storage devices like HDDs and SSDs to computer motherboards. An external SATA (eSATA) drive enclosure connects a SATA HDD or SSD to a computer via USB.

Consider Speed When Selecting External Storage Drives

The overall data transfer speed of an external storage device depends on the speed of the drive used and the speed of the connection between the drive and your computer. Connection interface options for external drives include USB 2.0, 3.0, and 3.1, as well as eSATA and Thunderbolt. USB 3.0 external hard drives are 10 times faster than models with USB 2.0.

Most brands offer hard disks in two drive speeds: 5400 and 7200 rpm. Each type has its merits. For example, if you’re looking for a portable Toshiba hard drive, pick one with a 5400 rpm HDD. It has a lower power draw and is quick enough for everyday use. Pick a model with a 7200 rpm HDD if you regularly transfer large files and need a desktop external drive.

Keep important files safe by regularly backing them up onto an external hard disk. Find the right one, including fast SSD options, in the extensive selection of portable storage devices at B&H Photo and Video.