ADATA UR350 256GB USB flash drive
Here you will find a detailed speed, performance and benchmark test review. Tested was the USB flash drive UR350 with 256GB (UR350-256G-RSR/BK) from the brand ADATA.
| Technical specifications (manufacturer information) | |
| Product image | 
|
| Manufacturer | ADATA |
| Model number | UR350-256G-RSR/BK |
| Capacity | 256 GB (232 GiB) |
| Read speed | 100 MB/s |
| Write speed | no information |
| Interface | USB 3.2 Gen 1x1 (5 Gbit/s) |
| Connector | USB Typ A |
| Controller | n/a |
Compare product Compared to the test winner*
Volume: E: Controller: Unknown Possible Memory Chip(s): Not available VID: 346D PID: 5678 Manufacturer: USB Product: Flash Disk Query Vendor ID: USB Query Product ID: Flash Disk Query Product Revision: 3.00 Physical Disk Capacity: 249314672640 Bytes Windows Disk Capacity: 249305104384 Bytes Internal Tags: ABYX-QADL File System: EXFAT Relative Offset: 32 KB USB Version: 3.10 Declared Power: 144 mA
We put the 256 GB ADATA USB flash drive through a detailed test. You can find the test result / test report here:
AS SSD Benchmark
Standard performance test
The standard test was performed with a 1 GB file. A total score of 0 points was achieved.
With an AS SSD total score of 0 (zero), the AS SSD benchmark could not be completed. The reason is extremely poor 4K values. These are then around 0.01MB/s, so the benchmark tool would need days to complete the 1GB test. Such USB flash drives are not really suitable for everyday use. It is better to invest a few euros more in a drive with better 4K values.
Copy performance test
A common everyday scenario is simulated here. Three test folders are created:
- ISO (folder with two large files)
- Program (folder with many small files)
- Game (folder with small and large files)
The three folders are copied using the Windows copy command (cache remains enabled). The real-world test from 11 February 2025 shows performance during simultaneous write and read operations. The lower the duration, the better.
| AS SSD Copy Benchmark | Transfer rate: | Duration: |
|---|---|---|
| ISO two large files |
39.51 MB/s |
27.18 s |
| Program typical program folder with many small files |
13.39 MB/s |
105.08 s |
| Game a game folder with small and large files |
31.17 MB/s |
44.30 s |
Compression performance test
Here, speed is measured depending on how compressible the data is.
CrystalDiskMark Benchmark
Similar to AS SSD, two sequential and two random performance tests are carried out here and the write and read speed (manufacturer specs: 100 MB/s) the ADATA USB flash drive is measured.
| CDM | Read [MB/s] | Write [MB/s] |
|---|---|---|
| SEQ1M Q8T1 |
150.68 |
39.13 |
| SEQ1M Q1T1 |
153.03 |
41.83 |
| RND4K Q32T16 |
9.21 |
0.11 |
| RND4K Q1T1 |
5.80 |
0.14 |
IOPS (Input/Output operations per second)
| CDM | Read [IOPS] | Write [IOPS] |
|---|---|---|
| SEQ1M Q8T1 |
143.70 |
37.30 |
| SEQ1M Q1T1 |
145.90 |
39.90 |
| RND4K Q32T16 |
2,247.30 |
26.10 |
| RND4K Q1T1 |
1,415.30 |
35.20 |
Average latency
| CDM | Read [µs] | Write [µs] |
|---|---|---|
| SEQ1M Q8T1 |
55,277.90 |
209,676.00 |
| SEQ1M Q1T1 |
6,848.49 |
25,014.60 |
| RND4K Q32T16 |
132,099.00 |
1,151,590.00 |
| RND4K Q1T1 |
706.09 |
28,314.90 |
HD Tune Pro long-term test
A long-term test was performed to fully utilize the storage. You can see at what point the cache (if present) becomes full and write performance drops. A test file of 4 GB was written to the medium.
HD Tune Pro Benchmark
HD Tune writes a 1 GB file to the 256 GB ADATA USB flash drive. The transfer data of the read speed is displayed graphically. The minimum, maximum and average values are also determined. The measured access time and burst rate are also shown.
ATTO Disk Benchmark
Here, a 256 MB file is written to the 256 GB ADATA USB flash drive multiple times. The I/O block size varies (from 512 bytes to 64 megabytes). The larger the blocks, the faster writing and reading usually becomes.
SSD-Z Benchmark
Similar to HD Tune, a 500 MB file is written to the 256 GB ADATA USB flash drive here. The transfer data is displayed. The more consistent the line, the better. Unfortunately, the tool no longer works correctly from around 4,000 MB/s and no line is displayed (and sometimes incorrect min/max data is shown).
Power consumption
The following screenshot shows the USB flash drive's power consumption at idle (standby) and during a read operation followed by a write operation. The drive consumes approx. 0.16 watts at idle. Maximum consumption was approx. 0.37 watts.
You can find information about the test system at the bottom of the homepage.
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