Tested to the Limit: Finding the Fastest USB Flash Drive
- Tenaka
- 11 minutes ago
- 13 min read
In this article, I’ll compare 11 USB pens to find out which one deserves to be crowned the fastest.
Buying a USB flash drive is often treated as a simple choice based on capacity and price, but performance can vary dramatically between products that appear similar on the packaging. Two 64 GB USB 3.x drives may cost almost the same, yet one can complete a large transfer several times faster than the other.
Advertised figures usually emphasise maximum read speed, while sustained write speed, cache behaviour, and mixed-file performance are often less obvious. A cheaper drive may save a few pounds at purchase but cost far more in waiting time when copying installation media, deployment files, backups, or large datasets.
Choosing the right USB drive therefore means looking beyond capacity and connector type and considering how it performs with the workload it will actually be used for.
This test was designed to compare a selection of USB flash drives using the same computer, source files, destination paths, filesystem, and PowerShell-based test process. The aim was not to reproduce a laboratory storage benchmark, but to measure the time taken to complete common file-copy operations under controlled and repeatable conditions.
USB Devices Tested
Device all purchased before 20 June 26 from Amazon | Cost | Advertised Read (MBs) | Advertised Write (MBs) | Type | |
1 | £16-00 | 60 | 200 | USB-A | |
2 | £8-48 | 60 | 100 | USB-A | |
3 | £9-99 | 70 | 20 | USB-A | |
4 | £13-58 | 60 | 10 | USB-A | |
5 | £49-95 | 2000 | 1300 | USB-C | |
6 | £39-99 | 500 | 550 | USB-A and USB-C | |
7 | £21-85 | 400 | 150 | USB-A and USB-C | |
8 | £15-08 | 150 | 150 | USB-A | |
9 | £21-49 | 130 | 30 | USB-A | |
10 | £12-65 | 400 | 625 | USB-C | |
11 | £25-70 | 400 | not known | USB-A and USB-C |
Test computer
All tests were carried out on a 2024 ASUS ROG Zephyrus G16. The laptop provides USB-A, USB-C, and Thunderbolt 4 connections, allowing compatible drives and dual-connector devices to be tested through the different connection types available on the same computer.
A second Samsung 990 Pro NVMe SSD was installed and dedicated to the USB performance tests. The Windows operating system, applications, page file, and normal background activity remained on the primary system drive.
The benchmark source files and local read-back destination were stored on the dedicated Samsung 990 Pro. This reduced the likelihood of operating-system activity competing with the benchmark for storage access and ensured that the local source and destination were considerably faster than the USB devices being tested.
The same source files and folder locations were used for every device.
Test process
Each USB device was formatted as NTFS using the default allocation unit size before testing. NTFS was required because the test included individual files larger than the 4 GB maximum file size supported by FAT32.
The benchmark was run using a PowerShell script written specifically for the test. At the start of each session, the script prompts for:
The name and model of the USB device.
The connection or port type being used.
The target drive, which was normally assigned as E:\.
The script then performs a write test by copying each test workload from the dedicated Samsung 990 Pro to the USB device. Once the write has completed, it performs a read test by copying the same data from the USB device back to a separate folder on the dedicated local SSD.
Only the actual copy operation is timed. File discovery, destination preparation, result validation, and cleanup are performed outside the timed section.
Robocopy is used to perform the transfers. Large-file tests use unbuffered I/O to reduce the effect of the Windows file cache. The mixed-file test uses a single copy thread so that every device is tested with the same level of concurrency.
After each operation, the script verifies that the destination contains the expected number of files and total number of bytes. The elapsed time, calculated transfer rate, test type, direction, device name, connection type, filesystem, disk information, and host details are written to CSV files.
Each device and connector combination is recorded as a separate test session. This is particularly important for drives with both USB-A and USB-C connectors, as the two interfaces can be compared independently.
Test workloads
Three different workloads were selected.
5 GB ISO file
The ISO test represents a typical large, continuous file such as Windows installation media, a recovery image, or a software distribution image.
A single large file gives a useful indication of sequential transfer performance. Its size is also large enough to expose some short-duration cache behaviour while remaining practical to repeat across several devices.
30 GB single file
The 30 GB file is used to measure sustained sequential performance.
Many flash drives can write quickly for the first few gigabytes by using a faster cache area. Once that cache is full, the transfer rate may fall significantly. A 30 GB file is large enough to show whether the advertised or initial write speed can be maintained throughout a longer transfer.
This test is therefore particularly useful when comparing short-burst write performance with sustained write performance.
Mixed-file collection
The mixed-file test contains 8 GB of data spread across 2,166 files.
This workload represents a more typical collection of deployment scripts, drivers, applications, documents, configuration files, and supporting content. Copying many files introduces additional filesystem and metadata operations, so performance can be substantially lower than when copying one large file.
This test is relevant to USB drives used for Windows deployment, technical support, software installation, and general file storage, where the workload is rarely limited to a single continuous file.
Recorded results
For each workload, the test records:
Write speed from the dedicated local SSD to the USB device.
Read speed from the USB device back to the dedicated local SSD.
Total elapsed time.
Decimal megabytes per second.
Binary mebibytes per second.
File count and total bytes.
Device and connection details.
Pass or fail validation status.
The resulting figures are then compared with the manufacturers’ advertised transfer speeds. Where a manufacturer only publishes an advertised read speed, the measured write result is reported separately rather than being compared against an unsupported write claim.
They are intended to show how the drives compare when completing the same practical workloads, rather than to represent the maximum theoretical bandwidth of the USB or Thunderbolt connection.
Advertised speed comparison
The advertised figures supplied with the test list were used as the comparison baseline, with one important adjustment. Some entries appear to have the advertised read and write columns reversed when compared with typical manufacturer wording. For consistency, the comparison below uses normalised read/write values where required.
The most important figure in this report is the 30 GB sustained write speed, because this shows how the device behaves once any short-term cache benefit has been exhausted.
Rank | Device and the best tested connection | Advertised read/write | 30 GB read | Read achieved | 30 GB write | Write achieved | 30 GB write time |
1 | Integral USSD 256GB Turbo Thunderbolt 4 | 2000 / 1300 | 2043 MB/s | 102% | 509 MB/s | 39% | 1m 03s |
2 | OSCOO SU001 128GB USB-C | 550 / 500 | 528 MB/s | 96% | 442 MB/s | 88% | 1m 13s |
3 | SanDisk Ultra Dual Drive Go Thunderbolt 4 | 400 / 150 | 412 MB/s | 103% | 71 MB/s | 47% | 7m 33s |
4 | Amazon Basics USB-C and USB-A Dual Port Thunderbolt 4 | 400 / unknown | 313 MB/s | 78% | 38 MB/s | — | 13m 57s |
5 | SanDisk Ultra Flair 64GB USB 3.0 USB-A | 150 / 150 | 153 MB/s | 102% | 33 MB/s | 22% | 16m 02s |
6 | Amazon Basics 128GB USB 3.1 USB-A | 130 / 30 | 141 MB/s | 108% | 30 MB/s | 100% | 17m 57s |
7 | Generic USB Stick 64GB USB 3.0 USB-A | 70 / 20 | 111 MB/s | 158% | 27 MB/s | 137% | 19m 37s |
8 | Kingston DataTraveler Kyson USB-A | 200 / 60 | 226 MB/s | 113% | 21 MB/s | 34% | 26m 04s |
9 | Kingston DataTraveler 70 DT70 Thunderbolt 4 | 400 / 625* | 87 MB/s | 22% | 15 MB/s | 2% | 35m 33s |
10 | Kingston DataTraveler Exodia USB-A | 100 / 60 | 94 MB/s | 94% | 14 MB/s | 23% | 38m 39s |
11 | Kingston DataTraveler G4 USB-A | 60 / 10 | 105 MB/s | 175% | 12 MB/s | 118% | 45m 24s |
*The Kingston DataTraveler 70 DT70 advertised figures require verification. The supplied figures do not align with the measured behaviour of the tested device, so the percentage comparison should be treated only as a comparison against the supplied listing values.
Main finding
The advertised read speeds were generally much closer to the measured results than the advertised write speeds.
Several devices met or exceeded their advertised read speed during the sustained 30 GB read test. This included the Integral Turbo-C, SanDisk Ultra Dual Drive Go, SanDisk Ultra Flair, Amazon Basics 128GB, Generic USB stick, Kingston Kyson, and Kingston G4.
Write performance was much less consistent. The biggest difference between advertised and measured performance appeared during the 30 GB write test.
The Integral Turbo-C reached 2043 MB/s read, slightly exceeding its advertised 2000 MB/s read figure. However, its sustained 30 GB write speed was 509 MB/s, which is only 39% of the supplied 1300 MB/s write figure.
The OSCOO SU001 was the strongest sustained performer relative to its advertised figures. It reached 528 MB/s read and 442 MB/s write, achieving approximately 96% of its advertised read speed and 88% of its advertised write speed.
Sustained write performance
The 30 GB write test produced the clearest separation between devices.
The fastest device, the Integral Turbo-C, completed the 30 GB write in 1 minute and 3 seconds. The slowest device, the Kingston DataTraveler G4, required 45 minutes and 24 seconds.
That makes the fastest result approximately 43 times faster than the slowest result for the same file, on the same laptop, using the same source SSD and the same test script.
For Windows deployment work, this difference is significant. A slow USB device can add a large amount of waiting time when copying operating system images, application installers, driver packs, scripts, and deployment content.
Cache behaviour
The 5 GB ISO test and 30 GB file test show whether a device can maintain its initial write speed over a longer transfer.
Device | 5 GB write | 30 GB write | Reduction |
SanDisk Ultra Flair | 81 MB/s | 33 MB/s | 58% lower |
Integral Turbo-C | 1219 MB/s | 509 MB/s | 58% lower |
SanDisk Ultra Dual Drive Go | 161 MB/s | 71 MB/s | 56% lower |
Amazon Basics USB-C and USB-A Dual Port | 51 MB/s | 38 MB/s | 24% lower |
The Integral Turbo-C almost reached its advertised write speed during the 5 GB ISO test, writing at 1219 MB/s. Over the larger 30 GB file, the average dropped to 509 MB/s.
This suggests the device is capable of very high short-burst writes, but that speed is not maintained across a larger sustained transfer.
The OSCOO SU001 behaved differently. It wrote the 5 GB ISO at 444 MB/s and the 30 GB file at 442 MB/s. That makes it one of the most consistent devices tested.
Mixed-file performance
The mixed-file test used 8 GB of data across 2,166 files. This is closer to a real deployment USB containing applications, scripts, drivers, configuration files, and supporting folders.
Rank | Device and the best tested connection | Mixed write | Mixed read |
1 | Integral Turbo-C — Thunderbolt 4 | 552 MB/s | 1312 MB/s |
2 | OSCOO SU001 — USB-C | 323 MB/s | 444 MB/s |
3 | SanDisk Ultra Dual Drive Go — Thunderbolt 4 | 72 MB/s | 335 MB/s |
4 | Amazon Basics USB-C and USB-A Dual Port — USB-C | 41 MB/s | 286 MB/s |
5 | SanDisk Ultra Flair — USB-A | 32 MB/s | 139 MB/s |
6 | Amazon Basics 128GB USB 3.1 — USB-A | 24 MB/s | 130 MB/s |
7 | Generic USB Stick 64GB USB 3.0 — USB-A | 22 MB/s | 104 MB/s |
8 | Kingston DT70 — Thunderbolt 4 | 13 MB/s | 82 MB/s |
9 | Kingston Exodia — USB-A | 13 MB/s | 89 MB/s |
10 | Kingston Kyson — USB-A | 6 MB/s | 177 MB/s |
11 | Kingston G4 — USB-A | 3 MB/s | 43 MB/s |
The mixed-file test was particularly damaging for the Kingston G4 and Kingston Kyson.
The Kyson read performance was strong at 177 MB/s for mixed files, but its mixed-file write speed was only 6 MB/s. This makes it unsuitable for workloads that involve repeatedly writing large collections of smaller files.
The Kingston G4 performed worst overall in the mixed-file write test at 2.75 MB/s.
Connector comparison
Several dual-connector or USB-C devices were tested through more than one connection type.
OSCOO SU001
Connection | 30 GB read | 30 GB write | Mixed write |
USB-C | 528 MB/s | 442 MB/s | 323 MB/s |
USB-A | 524 MB/s | 432 MB/s | 314 MB/s |
Thunderbolt 4 port | 524 MB/s | 411 MB/s | 238 MB/s |
The OSCOO produced very consistent large-file results across USB-A and USB-C. It did not benefit from the Thunderbolt 4 port because the device itself is the limiting factor rather than the laptop port.
SanDisk Ultra Dual Drive Go
Connection | 30 GB read | 30 GB write | Mixed write |
Thunderbolt 4 port | 412 MB/s | 71 MB/s | 72 MB/s |
USB-A | 400 MB/s | 70 MB/s | 52 MB/s |
USB-C | 412 MB/s | 69 MB/s | 53 MB/s |
The SanDisk Ultra Dual Drive Go was consistent across all connector types for large-file read and write performance. The Thunderbolt 4 connection did not materially improve large-file performance, indicating that the USB drive is the limiting factor.
Amazon Basics USB-C and USB-A Dual Port
Connection | 30 GB read | 30 GB write | Mixed write |
USB-C | 319 MB/s | 38 MB/s | 41 MB/s |
Thunderbolt 4 port | 313 MB/s | 38 MB/s | 41 MB/s |
USB-A | 286 MB/s | 38 MB/s | 40 MB/s |
The Amazon Basics dual-port drive delivered consistent write performance across all three tested connections. Read performance was better through USB-C and Thunderbolt 4 than USB-A, but write speed remained around 38 MB/s regardless of connector.
This makes it a reasonable read-focused device, but not a strong choice for repeated large writes.
Integral Turbo-C
Connection | 30 GB read | 30 GB write | Mixed write |
Thunderbolt 4 port | 2043 MB/s | 509 MB/s | 552 MB/s |
USB-A via adapter | 1065 MB/s | 467 MB/s | 368 MB/s |
USB-C | 1068 MB/s | 464 MB/s | 410 MB/s |
The Integral Turbo-C was the fastest device tested. It delivered the highest overall read performance through the Thunderbolt 4 port, reaching 2043 MB/s on the 30 GB read test. It also produced the fastest sustained write result, completing the 30 GB write at 509 MB/s.
Performance remained strong through both USB-C and the USB-A adapter. Over USB-C, the drive reached 1068 MB/s read and 464 MB/s sustained write. Through the USB-A adapter, it produced a very similar large-file result, reaching 1065 MB/s read and 467 MB/s sustained write.
Thunderbolt 4 provided the strongest overall performance, especially for read speed and mixed-file transfers. However, the USB-C and USB-A adapter results show that the Integral Turbo-C remains a very fast option even when Thunderbolt is not available
Kingston DataTraveler 70
Connection | 30 GB read | 30 GB write | Mixed write |
Thunderbolt 4 port | 87 MB/s | 15 MB/s | 13 MB/s |
USB-C | 29 MB/s | 10 MB/s | 9 MB/s |
The Kingston DataTraveler 70 DT70 was one of the weakest performers in the test. Its read speed was consistent at around 84–87 MB/s, but its write speed remained between 13–15 MB/s across all workloads. The 30 GB sustained write completed at 14.64 MB/s and took 36 minutes and 41 seconds.
Price-to-performance
Using sustained 30 GB write speed divided by purchase price, the ranking changes slightly.
Rank | Device | Price | 30 GB write | Write speed per £ |
1 | OSCOO SU001 | £39.99 | 442 MB/s | 11.05 MB/s per £ |
2 | Integral Turbo-C | £49.95 | 509 MB/s | 10.19 MB/s per £ |
3 | SanDisk Ultra Dual Drive Go | £21.85 | 71 MB/s | 3.26 MB/s per £ |
4 | Generic USB Stick | £9.99 | 27 MB/s | 2.74 MB/s per £ |
5 | SanDisk Ultra Flair | £15.08 | 33 MB/s | 2.22 MB/s per £ |
6 | Kingston Exodia | £8.48 | 14 MB/s | 1.64 MB/s per £ |
7 | Amazon Basics USB-C and USB-A Dual Port | £25.70 | 38 MB/s | 1.50 MB/s per £ |
8 | Amazon Basics 128GB USB 3.1 | £21.49 | 30 MB/s | 1.39 MB/s per £ |
9 | Kingston Kyson | £16.00 | 21 MB/s | 1.29 MB/s per £ |
10 | Kingston DT70 | £12.65 | 15 MB/s | 1.16 MB/s per £ |
11 | Kingston G4 | £13.58 | 12 MB/s | 0.87 MB/s per £ |
The OSCOO SU001 remains the best value when using its highest measured sustained write result, achieving 11.05 MB/s per £.
The Integral Turbo-C remains close behind at 10.19 MB/s per £, while also delivering the fastest absolute performance in the test. The USB-A adapter result shows that it remains a high-performance option even when Thunderbolt 4 is not available.
Initial awards
Fastest overall
Integral USSD 256GB Turbo-C USB 3.2 Gen 2x2
The Integral was the fastest device in the test by a large margin. It reached 2043 MB/s read and 509 MB/s sustained write through the Thunderbolt 4 port.
It is the best option where maximum transfer speed is the priority. Thunderbolt 4 delivered the highest read speed, but the USB-C and USB-A adapter results also remained very strong, both exceeding 460 MB/s sustained write in the 30 GiB test.
Best all-round USB drive
Integral USSD 256GB Turbo-C USB 3.2 Gen 2x2
The Integral was the fastest device in the test by a large margin. It reached 2043 MB/s read and 509 MB/s sustained write through the Thunderbolt 4 port, making it the clear performance leader.
It also performed strongly over USB-C and through the USB-A adapter, with both connections delivering more than 460 MB/s sustained write in the 30 GB test. Thunderbolt 4 provided the highest read speed, but the Integral remained a very fast option across all tested connection types.
Best conventional dual-connector flash drive
SanDisk Ultra Dual Drive Go
The SanDisk Ultra Dual Drive Go was much slower than the Integral and OSCOO on sustained writes, but it performed consistently across USB-A, USB-C, and Thunderbolt 4 ports.
Its read speed was close to the supplied advertised figure, making it a useful read-focused deployment or support drive.
Best budget surprise
Generic USB Stick 64GB USB 3.0
The generic USB stick exceeded its supplied advertised figures and outperformed several branded budget drives in sustained write speed.
It was not fast, but for its price it performed better than expected.
Most consistent against advertised write speed
Amazon Basics 128GB USB 3.1
The Amazon Basics 128GB USB 3.1 drive measured 29.92 MB/s against a supplied advertised write speed of 30 MB/s. It was not a fast device, but it was one of the few drives where the sustained write result closely matched the supplied write figure.
Weakest result
Kingston DataTraveler G4
The Kingston G4 had the slowest sustained 30 GB write time and the weakest mixed-file write performance. It completed the 30 GB write at 11.82 MB/s and the mixed-file write at only 2.75 MB/s.
For a Windows deployment USB, this level of write performance would be a significant limitation.
Conclusion
The final results show that USB flash drive performance cannot be judged by capacity, connector type, or USB version alone.
Several drives achieved strong read speeds, and many came close to or exceeded the supplied advertised read figures. Sustained write performance was far less predictable. Some devices dropped sharply when moving from the 5 GB ISO test to the 30 GB sustained write test, suggesting that short-burst performance can give a misleading impression of real-world behaviour.
The Integral Turbo-C is the fastest device tested, but the OSCOO SU001 is the strongest all-round result when consistency, sustained write speed, connector flexibility, and price are considered together.
The main practical finding is simple: two USB drives with similar packaging and USB version labels can behave completely differently. In this test, the difference between the fastest and slowest 30 GB write result was more than 40 times.
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