Specifications
| Brand | Lexar |
|---|---|
| Storage Capacity | 128 GB |
| Usb Standard | USB 3.2 Gen 1 |
| Read Speed | 100 MB/s |
| Write Speed | 100 MB/s |
| Connector Type | Dual USB-A/C |
| Form Factor | Swivel |
| Security Features | Hardware Encryption |
Pros
- High capacity
- High write speed
- Strong security
Cons
- Clunky security workflow
- Heating during use
The Verdict
The Lexar D40E is a dual USB-A and USB-C flash drive rated at 100 MB/s for both reads and writes. It is a solid pick for OTG use, but the security workflow feels clunky and the drive can get hot during longer transfers, which can slow the experience.
Who it's for: People who need one drive to move files between phones, tablets, and computers will like the swivel dual-connector design, and they can live with slower, more annoying steps when they want to use the hardware encryption.
Who should skip it: Buyers who hate extra steps for locking and unlocking data, or who regularly move large files for long stretches, should look elsewhere due to the heating and the awkward security workflow.
In-Depth Review
Performance
Lexar rates the D40E for transfer speeds up to 100 MB/s and lists both read_speed: 100 MB/s and write_speed: 100 MB/s on its USB 3.2 Gen 1 spec line. In practice, that is enough for quick copies of large folders, installers, and media files when you start a transfer and stay on a compatible port.
However, this pillar scores 7.4, which maps to the template phrase "Consistently fast large-file transfers". That is a fair fit for what these specs imply. USB 3.2 Gen 1 class drives can look great for the first chunk of a file, then slow when sustained writes hit controller and thermal limits. The product also lists a real-world drawback in the guide: heating during use. Heat often changes sustained write behavior, even if the initial copy looks close to the label.
If you plan to copy huge backups in one long session, treat the 100 MB/s number as a ceiling, not a promise. For shorter bursts, the D40E should feel fast. For long uploads to the drive, expect some drop from the peak, especially if you are using it on battery-powered devices that throttle USB performance.
Capacity
The D40E comes in 128 GB storage, and the listing ties that capacity directly to the model name: "Lexar D40E 128GB". In other words, the label and the advertised storage match, so the capacity pillar hits 8.1 with the phrase "Plenty of usable space delivered".
With 128 GB and USB 3.2 Gen 1 class speeds, this is a sensible size for photo sets, app installers, and mixed media collections. It also works for backup packs that include multiple file types, not just one big disk image. The swivel body and dual connector design also make it easier to move that content between devices without finding the right adapter.
Because the pillar is about trust and not just big numbers, it helps that this drive is presented as a straightforward 128 GB product, not a confusing rebranded capacity situation. Still, your real usable space will be lower than the label due to formatting, and the secure storage workflow can change how you manage files over time.
Build Quality
Build is a mixed bag. The D40E uses a swivel mechanism to switch between its dual USB-A/C connectors. That kind of design helps on the go, but it adds moving parts. Your experience will depend on how often you plug and unplug it, and how you treat the connector when it extends.
This pillar scores 7.8 and aligns with "Frequent plugging, no wobble" as the target feel. The design choice matters here. With a connector that can swap between USB types, you avoid awkward third-party adapters. That can reduce strain on your phone or laptop port and keep the drive more stable during short sessions.
At the same time, the guide flags heating during use. Heat does not automatically mean a doomed drive, but repeated warm operation can stress plastics and internal components. For a swivel unit, I would still recommend careful handling, especially when you are copying large files and the housing starts to feel hot.
Security
Security is where the D40E has the sharpest trade-off. The specs list Hardware Encryption and cite 256-bit AES in the description. That is a strong number. This pillar scores 6.6 and matches the template phrase "Security setup feels clunky".
The mini-guide repeats the user-facing issue in plain terms: clunky security workflow. That matters more than encryption strength for most people. A drive can use 256-bit AES and still frustrate you if the unlock process takes extra steps or does not behave smoothly across devices.
Security workflow and heat can also interact. The guide notes Heating during use. If the security process keeps the drive active longer, the drive may run warmer during encrypted transfers. If you only need basic privacy, this model works. If you want fast, repeatable locking and unlocking, the friction is real.
Value
Value depends on balancing speed, build, and security against your tolerance for trade-offs. The D40E lists 100 MB/s for both reads and writes under USB 3.2 Gen 1, plus 128 GB capacity. It also includes hardware encryption with 256-bit AES, which is more than what many basic flash drives include.
With a score of 8.3, the value pillar maps to "Fair price, solid day-to-day performance". That is consistent with the spec profile: a dual-connector swivel body that targets everyday portability, and speed numbers that fit routine file transfers. The downsides mentioned in the guide, clunky security workflow and heating during use, reduce how often you will want to rely on it for long, repeat encrypted sessions.
So the value story is practical. For fast copies and cross-device use, the combination of dual USB-A/C and 128 GB makes sense. For security-heavy workflows where you unlock frequently, the process may slow you down. This is a good fit if your use case matches the design intent, not if you need frictionless encryption on every transfer.
Frequently Asked Questions
Is the Lexar D40E 128GB USB flash drive USB 3.2 Gen 1 compatible with my laptop?
Yes. The drive uses USB 3.2 Gen 1 and should work in laptops and PCs that have a USB-A or USB-C port. It also has a dual USB-A/C connector, which helps avoid needing an adapter.
What speeds can I expect from the Lexar D40E 128GB for large file transfers?
Lexar lists read and write speeds of 100 MB/s each. In real use, you may see lower speeds once the internal transfer buffer fills, especially for long writes. If you move large videos or make backups, test with your most common file sizes.
How much storage do I actually get on the Lexar D40E 128GB drive?
The advertised capacity is 128 GB. Like most flash storage, your computer will show slightly less usable space after formatting, because of how storage is measured and reserved space.
Does the D40E use a swivel design, and will it block nearby USB ports?
It uses a swivel form factor, which lets you rotate the connector into position when you plug it in. In tight layouts, it can still compete for space with adjacent ports, but the dual USB-A and USB-C design helps you choose the best orientation.
How does hardware encryption work on this Lexar drive, and is the workflow easy?
The D40E includes hardware encryption. Some users find the security workflow clunky, so setup and unlocking can feel slower than expected. Plan for extra steps if you frequently access the drive across different computers.
Why does my Lexar D40E get warm during use, and is that normal?
Heating can happen during longer read or write sessions, since USB 3.2 Gen 1 transfers at up to around 100 MB/s. A common con with this model is heating during use. If it feels hot to the touch or slows down, let it cool and avoid continuous long writes back to back.
Final Verdict
This Lexar 128GB drive is a solid pick for people who need reliable OTG storage and want strong overall value. It delivers high write speed and ample capacity. Still, the security setup feels clunky, and it can heat up during sustained use. That combo may frustrate buyers who transfer large files often and rely on frequent secure access.
If you can live with a more awkward security workflow and occasional warmth under load, this is a sound pick for everyday backups and media transfers.
