Portable SSDs

What portable SSDs are

SSD stands for solid-state drive. Instead of the spinning platters of a hard disk drive, it keeps data on NAND flash memory, which holds its contents with the power off.

• No moving parts: That gives SSDs faster access, silent running and better resistance to physical shock than hard drives.
• Powered by the cable: Most draw power from the port they plug into; OWC’s Envoy Ultra, for one, is bus-powered with a built-in cable.
• Pocket size: Samsung’s T7 Shield measures 88 × 59 × 13 mm and weighs 98 g.
• Made for the road: Samsung pitches the T7 Shield for outdoor photo shoots and travel, with an aluminum body under a rubber skin.
• Who makes them: Samsung, SanDisk, Lexar, LaCie, OWC, Corsair and Sharge among others; Micron ended Crucial consumer shipments in February 2026.

How they work

Inside is a small circuit board with flash chips and a controller. The controller manages the flow of data between the flash and the computer, spreads writes evenly across the cells and watches the temperature.

• A fast cache: Many SSDs hold data in a small DRAM cache while it is being written to the flash.
• When the cache fills: In StorageReview’s tests, Samsung’s P9 ran out of cache after about 150 GB of writing and slowed to about 540 MB/s.
• The link sets the ceiling: USB 3.2 Gen 2 signals at 10 Gbit/s, Gen 2x2 at 20, USB4 at 20, 40 or 80, and Thunderbolt 5 at 80.
• Hardware encryption: Samsung’s T7 Shield and T9 encrypt data with AES 256-bit in hardware, unlocked with a password you set.
• Heat control: Samsung’s T9 uses Dynamic Thermal Guard; Sharge’s Disk Pro adds a small fan; SanDisk’s PRO-G40 uses an aluminum core.

Types

• 10 Gbps drives: USB 3.2 Gen 2 models such as Samsung’s T7 Shield are rated up to 1,050 MB/s read.
• 20 Gbps drives: USB 3.2 Gen 2x2 models such as Samsung’s T9 and Lexar’s ES5 are rated up to 2,000 MB/s on a Gen 2x2 port.
• USB4 drives: 40 Gbps models such as Samsung’s P9, launched in 2026, are rated up to 4,000 MB/s.
• Thunderbolt drives: OWC’s Envoy Ultra uses Thunderbolt 5 and is rated over 6,000 MB/s; SanDisk’s PRO-G40 uses Thunderbolt 3 with a USB fallback.
• Magnetic phone drives: MagSafe-compatible models such as Lexar’s ES5 snap to the back of a phone and record video straight to the drive.
• Drive and hub in one: Sharge’s Disk Pro adds HDMI, USB-C and USB-A ports to a built-in SSD.
• Rugged drives: Sealed shells with dust, water and drop ratings; SanDisk rates the PRO-G40 IP68 and crush-resistant to 4,000 lb.

What to look for

• Match the port: Rated speeds need a matching port: Lexar rates the ES5’s 2,000 MB/s on hosts with USB 3.2 Gen 2x2, and Samsung’s T7 Shield needs USB 3.2 Gen 2 with UASP.
• The IP rating: The first digit is dust, the second water: IP65 is dust-tight and resists water jets; IP67 survives immersion to 1 m; IP68 goes deeper.
• A drop rating: Samsung drop-tested the T7 Shield with four 3 m falls onto a steel floor.
• Sustained writes: A long copy can outrun the cache; Tom’s Hardware saw the Sharge Disk Pro hold above 900 MB/s through a 30-minute write test.
• Room to grow: Tom’s Hardware suggests at least 50% more capacity than the photos and videos you already have.
• Weight: From 80 g for Lexar’s ES5 to 341 g for OWC’s Envoy Ultra.
• Warranty: Three years on the T7 Shield; five on Samsung’s T9, Lexar’s ES5, SanDisk’s PRO-G40 and OWC’s Envoy Ultra.

On the plane and on the trip

• Security screening: TSA asks travelers to take electronics larger than a cell phone out of carry-on bags and put them in a bin for X-ray.
• iPhone backups: Apple says iPhone 15 Pro and later Pro models move data at up to 10 Gbit/s with a USB 3 cable and can record ProRes video straight to an external drive at up to 4K 60 fps.
• Android phones: Samsung lists Android Lollipop or later for the T7 Shield; Lexar says the ES5 also records Samsung Pro Video.
• Keep three copies: CISA’s 3-2-1 rule: three copies of important files, on two kinds of media, with one stored offsite.
• At the border: CBP may inspect electronic devices, including files on an external drive; in fiscal 2025 it searched the devices of under 0.01% of arriving international travelers.
• Encrypted drives: CBP says a device it cannot inspect because of a passcode or encryption may be detained.
• One format for all: Samsung ships the T7 Shield in exFAT, which Windows, macOS and Android read and write; Time Machine on a Mac needs APFS.

Limits and care

• Not a lone backup: Tom’s Hardware notes portable drives are small enough to lose or leave behind; keep another copy at home or in the cloud.
• Data fades unpowered: Consumer SSDs worn to their rated life may start losing data after about a year without power, sooner when hot.
• Ratings are lab results: Samsung says the T7 Shield’s IP65 and drop results come from controlled tests, and water, dust and drop damage are not covered by warranty.
• Eject before unplugging: Samsung says to use Eject or Safely Remove Hardware, and not to pull the cable with force.
• Temperature and humidity: Samsung recommends 5–35 °C (41–95 °F) and 10–80% humidity; dry the drive thoroughly if it gets wet.
• Cleaning: Wipe with a soft cloth; Samsung says no water, chemicals or detergent.
• Forgotten passwords: With encryption on, a lost password means a factory reset that erases every file, Samsung warns.

A short history

Fujio Masuoka invented flash memory at Toshiba in 1980. SanDisk’s founders patented the flash-based SSD in 1989, and the company shipped a 20 MB SSD for IBM laptops in 1991.

• November 2006: Microsoft introduces exFAT, the file system many portable SSDs still ship with.
• February 2011: Thunderbolt arrives on Apple’s MacBook Pro.
• January 2015: Samsung unveils the Portable SSD T1 at CES, rated up to 450 MB/s over USB 3.0.
• August 2019: The USB4 specification is released.
• April 2022: Samsung launches the T7 Shield, IP65-rated and drop-tested to 3 m.
• December 2025: Micron announces its exit from the Crucial consumer business to focus on faster-growing markets.
• June 2026: LaCie’s Rugged SSD4 and Rugged SSD Pro5 are reported discontinued a year after launch, amid a NAND flash shortage.
• August 2026: Samsung shows the P9, which it calls the first 8 TB USB4 portable SSD, at Gamescom.