The Lexar SL500 (starts at $129.99 for 1TB; $179.99 for 2TB as tested) is a thin, sleek, and highly portable external SSD available in capacities up to 4TB. It provides 256-bit AES encryption so you needn't worry about your data falling into the wrong hands should the drive be lost or stolen. To get close to the SL500's blazing peak throughput speeds, however, you'll need a system with an uncommon USB 3.2 Gen 2x2 interface—plugged into a near-ubiquitous USB 3.2 Gen 2 port, the Lexar reverts to speeds typical of today's mainstream external SSDs. The same is true of our two Editors' Choice honorees in this category, the ADATA SD810 and the Crucial X10 Pro; those drives represent slightly better values than the SL500.

Design: A Tiny, Take-Anywhere Speedster

At 0.3 by 2.1 by 3.3 inches (HWD), the Lexar SL500 is roughly the size of a credit card and among the thinnest external SSDs we've seen. It weighs just 1.5 ounces. Matte black with silver trim (including a Lexar logo on top), the drive's aluminum frame is bowed slightly, giving the short ends a convex appearance as shown in the photo below. A USB-C port is centered on one end, next to a tiny status LED that glows when the drive is active. The SL500 comes with a USB-C-to-USB-C cable for connecting to a computer or other device.

(Credit: Joseph Maldonado)

Again, the SL500's USB-C port supports the USB 3.2 Gen 2x2 standard for maximum throughput up to 20Gbps. To avail yourself of this searing speed, you'll need either a computer with a compatible port (relatively few models, even recent ones, have one) or a Gen 2x2 desktop expansion card. Check out our USB-C explainer for more on the differences among the various flavors of USB interface.

Furthermore, with USB4 starting to show up in PCs and on a few external drives, USB 3.2 Gen 2x2 may be superseded without ever coming into its own. (To be fair, both USB4 SSDs we've reviewed, the OWC Express 1M2 and Oyen Digital U34 Bolt, have had teething problems and stringent hardware compatibility requirements.) All that said, if you have a rig with a USB-C port that supports the Gen 2x2 standard, you can get the most out of the SL500.

Price-wise, the Lexar is in the midrange for a Gen 2x2 SSD, costing more than the ADATA SD810 at all its capacities (up to 4TB) and about the same as several other drives. At 2TB, it costs a bit less than the Crucial X10 Pro, though the Crucial is considerably cheaper at the 4TB level.

Software and Security: Uncrackable Encryption

The SL500 includes Lexar's DataShield software, which lets you enable AES 256-bit hardware-based encryption. With the software installed on your computer, you can set a password for the drive. AES encryption is essentially uncrackable, even when subjected to a brute-force attack.

The drive can be used with Windows PCs, Macs, Android devices, and the iPhone 15; with the last, you can record video in Apple's Pro Res format and save it directly to the SL500 while the drive is connected to your phone.

Unlike the ADATA SD810, which is rated drop-proof according to the MIL-STD-810G 516.6 impact resistance standard and whose ingress protection rating of IP68 makes it effectively impervious to dust and brief immersion in water, the SL500 claims no ruggedness cred. Lexar backs the drive with a five-year warranty, which is typical of external SSDs from major brands.

Testing the Lexar SL500: Nice Speed, if You Can Get It

We test USB 3.2 Gen 2x2 external SSDs using PC Labs' Windows 10 storage testbed, a desktop PC built on an Asus Prime X299 Deluxe motherboard with an Intel Core i9-10980XE Extreme Edition CPU and an Nvidia GeForce graphics card. We use the motherboard's native 10GBps USB 3.2 Gen 2 port for testing most drives; for 20Gbps Gen 2x2 drives like the SL500 we use a Gen 2x2 port added via an Orico PCIe expansion card.

We subjected the SL500 to our usual suite of external solid-state drive benchmarks, comprising Crystal DiskMark 6.0, the PCMark 10 data drive benchmark, the 3DMark Storage gaming test, Blackmagic's Disk Speed Test, and our own folder transfer test. As the drive comes preformatted in exFAT, which is compatible with both Macs and Windows machines, we ran the latter two tests first on an Apple MacBook Pro. Then we reformatted the drive in NTFS to run Crystal DiskMark, PCMark 10, and 3DMark on our Windows testbed.

Crystal DiskMark's sequential speed tests provide a traditional measure of drive throughput, simulating best-case, straight-line transfers of large files. The Mac-based Blackmagic clocks a drive's performance in reading and writing video in a variety of formats. The PCMark 10 Data Drive test measures an SSD's aptitude in performing a variety of everyday tasks.

In all our tests, the SL500 posted scores typical of a USB 3.2 Gen 2x2 SSD. Its Crystal DiskMark and Blackmagic results were in line with its Gen 2x2 competitors, except for the much faster Samsung Portable SSD T9. The T9 officially uses a Gen 2x2 interface, but in our MacBook-based Blackmagic testing put up much better numbers than should have been possible unless it has Thunderbolt or USB4 connectivity.

The sequential read speeds for all our Gen 2x2 drives in Crystal DiskMark were so similar as to be effectively identical. The SL500's file transfer test results were average, and in both PCMark 10 and 3DMark Storage, its scores were on the high side of a narrow range of values among our comparison drives.

Verdict: A Sleek, Secure, and Speedy SSD

The ultra-slim Lexar SL500 is a good take-anywhere external SSD. This featherweight drive can easily fit into a pocket, and should it go missing, you needn't worry about your data being raided if you've enabled the drive's AES encryption. The SL500 comes in capacities up to 4TB and produced solid results in all our benchmarks, with speeds typical of a drive with a USB 3.2 Gen 2x2 interface.

(Credit: Joseph Maldonado)

There are quite a few other highly capable Gen 2x2 SSDs on the market, including the two aforementioned Editors' Choice award winners, the ADATA SD810 and Crucial X10 Pro. The Lexar is pricier than the ADATA and lacks that model's ruggedization, but unlike the SD810 it provides AES hardware-based encryption. The Crucial X10 Pro also has AES encryption and adds basic ruggedization features.

Though the SL500 falls short of an Editors' Choice nod, it's still a capable external SSD well worth considering if you are in the market for a drive with USB 3.2 Gen 2x2 speed—meaning, of course, that you have or are willing to build or modify a PC to support that standard.