TEST: Netac ZX20 II 1TB external SSD
Here you can find a detailed performance and benchmark test of the external SSD ZX20 II with 1TB (ZX20 II 1TB) from Netac.1265
0,16 $
| Technical data | |
| Image | 
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| Manufacturer | Netac |
| Model number | ZX20 II 1TB |
| Storage capacity | 1024 GB (931 GiB) |
| pSLC-Cache | 25 GB approx. |
| Read speed | 2000 MB/s |
| Write speed | 1800 MB/s |
| Interface | USB 3.2 Gen 2x2 (20 Gbit/s) |
| Connection | USB Typ C |
| Size (LxWxH) | 73 x 45 x 8 mm |
| Weight | 49 gram |
| Price | ca. 164 AUD (= 0,16 $ / GB) |
| Paid link | Buy on Amazon |
Compared to the top performer*
*) Test result evaluated according to AS SSD Score within the same size.
AS SSD Benchmark
Standard performance test
The standard test was performed with a 5 GB file. A total score of 1265 points was achieved.
| AS SSD | Read: | Write: |
|---|---|---|
| Seq in megabytes per second |
1906,52 MB/s |
1708,82 MB/s |
| 4K in megabytes per second |
25,12 MB/s |
78,57 MB/s |
| 4K-64Thrd in megabytes per second |
256,11 MB/s |
304,93 MB/s |
| Access time in milliseconds |
0,048 ms |
1,316 ms |
| Score | 472 |
554 |
| Total score | 1265 |
|
Copy Performance Test
A common everyday situation 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 (the cache remains enabled). The practical test of November 24, 2025 shows the performance for simultaneous write and read operations. The lower the duration, the better the performance.
| AS SSD Copy-Benchmark | Transfer rate: | Duration: |
|---|---|---|
| ISO two large files |
895,69 MB/s |
2,57 s |
| Program many small files |
138,82 MB/s |
50,70 s |
| Game small and large files |
524,97 MB/s |
13,16 s |
Compression Performance Test
Here, the writing and reading speed of the SSD is measured depending on the compressibility of the data (according to the manufacturer, these should be 2000MB/s and 1800MB/s respectively).
CrystalDiskMark Benchmark
Here, two sequential and two random performance tests are performed, similar to the ones performed on the AS SSD.
| CDM | Read [MB/s] | Write [MB/s] |
|---|---|---|
| SEQ1M Q8T1 |
2078,11 |
1875,16 |
| SEQ1M Q1T1 |
1878,42 |
1710,78 |
| RND4K Q32T16 |
236,66 |
368,50 |
| RND4K Q1T1 |
28,80 |
86,21 |
Input/Output operations per second
| CDM | Read [IOPS] | Write [IOPS] |
|---|---|---|
| SEQ1M Q8T1 |
1.981,80 |
1.788,30 |
| SEQ1M Q1T1 |
1.791,40 |
1.631,50 |
| RND4K Q32T16 |
57.778,60 |
89.966,80 |
| RND4K Q1T1 |
7.031,50 |
21.046,10 |
Average latency
| CDM | Read [µs] | Write [µs] |
|---|---|---|
| SEQ1M Q8T1 |
4.033,13 |
4.465,36 |
| SEQ1M Q1T1 |
558,00 |
612,55 |
| RND4K Q32T16 |
8.844,98 |
5.685,73 |
| RND4K Q1T1 |
142,07 |
47,39 |
HD Tune Pro Endurance test
A long-term test was performed here to make full use of the memory capacity. You can see when a cache is full and the writing performance decreases.
A test file of 200 GB was written to the medium.
After approx. 25 GB, the pSLC-Cache was full and the performance was throttled.
The average read speed was 1951 MB/s and the average write speed was 1161 MB/s.
ATTO Disk Benchmark
Here, a 256 MB file is written several times to the Netac external SSD . The I/O block size varies (from 512 bytes to 64 megabytes). The larger the blocks, the faster they can be written and read.
SSD-Z Benchmark
Similar to HD Tune, a 500 MB file is written to the Netac external SSD here. is written. The transfer data is displayed. The more constant the line, the better.
Information about the test system can be found at the bottom of the home page.
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