- Obtained from: AliExpress
- Price paid: $2.99
- Advertised capacity: 32GB
- Size of protected area: 83,886,080 bytes
- Speed class markings: Class 10, U1, V10, A2
- CID data:
- Manufacturer ID:
0x1d* - OEM ID:
0x4144(ASCII:AD)*
- Manufacturer ID:
| Sample # | 1 | 2 | 3 | Average |
|---|---|---|---|---|
| Logical capacity | 31,037,849,600 bytes | 31,954,305,024 bytes | 31,954,305,024 bytes | 31,648,819,883 bytes |
| Physical capacity | 31,037,849,600 bytes | 31,954,305,024 bytes | 31,954,305,024 bytes | 31,648,819,883 bytes |
| Fake/skimp flash | Skimpy (3.01% skimp) | Skimpy (0.14% skimp) | Skimpy (0.14% skimp) | Skimpy (0.14% skimp) |
| Adjusted skimp | 2.74% | -0.12% | -0.12% | -0.12% |
| Product name | 0x5344202020 (ASCII: SD | 0x5553440000 (ASCII: USD) | 0x5553440000 (ASCII: USD) | N/A |
| Product revision | 0x10 | 0x20 | 0x20 | N/A |
| Serial number | 0x000000e8 | 0x00000dac | 0x00000eb9 | N/A |
| Manufacture date | Jan 2021 | Feb 2023 | Feb 2023 | N/A |
| Sequential read speed (MB/sec) | 94.32 | 93.78 | 93.78 | 93.96 |
| Sequential write speed (MB/sec) | 20.73 | 28.78 | 28.31 | 25.94 |
| Random read speed (IOPS/sec) | 2,817.46 | 1,097.46 | 959.47 | 1,624.80 |
| Random write speed (IOPS/sec) | 401.98 | 264.57 | 262.53 | 309.69 |
| Read/write cycles to first error | 3,778 | 1,558 | 0 | 1,779 |
| Read/write cycles to 0.1% failure threshold | 3,790 | 1,632 | 1,586 | 2,336 |
| Read/write cycles to complete failure | 3,790 | Not yet determined | 1,602 | 2,696 |
| Total days to complete failure | 274 | Not yet determined | 84 | 179 |
| Card reader used | JJC CR-UTC4AC | JJC CR-UTC4AC | JJC CR-UTC4AC | N/A |
| Package front |  |  |  | N/A |
| Package back |  |  |  | N/A |
| Card front |  |  |  | N/A |
| Card back |  |  |  | N/A |
* This manufacturer ID/OEM ID is pretty well known to be associated with ADATA.
Discussion
ADATA is a brand that I’ve come across a few times now, during both my Amazon and AliExpress searches. They appear to be a fabless manufacturer based out of Taiwan. Seeing as how they’re a member of the SD Card Association, I’ll lump them in with the “name-brand” cards.
There appear to be (at least) two versions of this card floating around out there, possibly from two different manufacturers. One appears to be a little bit older (from early 2021), while the newer version is more recent (early 2023). Both versions performed about the same on sequential read tests; however, the older version scored slightly worse on sequential write tests, slightly better on random write tests, and significantly better on random read tests. On the downside, it was skimpier than the newer version.
Performance results for these cards were kinda all over the place. For example, as I mentioned above, sample #1 got a random read speed that was almost three times higher than the other two. Sample #2 also got pretty horrible read speeds on its first attempt, but were more in line with the scores from sample #3 on the second attempt.* Some samples got scores that were above average, while some got scores that were below average.
With the exception of sample #1’s random read scores, all scores came within one standard deviation of average. More specifically: sequential read speeds were above average, while all other scores (again, with the exception of sample #1) were below average. Sample #1 had a random read score that was more than one standard deviation above average; its sequential write score was below average, while its random write score was just average.
Endurance tests for all three cards are still ongoing:
- Sample #1 went for quite a while without any issues — albeit pretty slowly, because it was plugged into the same reader as sample #2 for the longest time, and sample #2 was stuck giving constant I/O errors — so the reader was spending most of its time dealing with those. However, once I moved it to its own reader, it continued right along until it got to round 3,779 — at which point about 1,100 sectors experienced bit flip errors. This continued for only a few more rounds: during round 3,791, the card made itself read-only.
- Sample #2’s first error was a series of bit flips, affecting two sectors, during round 1,559. It has survived 1,664 read/write cycles in total so far. As I mentioned above, it’s currently experiencing a high number of I/O errors on read operations. I’m hoping that my program will eventually determine which parts of the card are bad and avoid those in future rounds; however, it may take some time for this to happen.
- Sample #3’s first error was a 42,624-sector wide address decoding error during round 1. It continued to experience sector degradation over the following rounds, until it got to the point — during round 1,603 — where it stopped responding to commands.
* I don’t normally re-run performance tests — because performance can go down the longer a card has been in use — however, this card is being tested on my son’s server, on which he had some other workloads going that might have affected the outcome, and he needed to reboot the machine shortly after the endurance test started. This meant that I had to start my program over from scratch, because my program will refuse to resume from a save state if the endurance test hasn’t completed at least the first round of testing. The results of the second performance test came out much better, so I decided to go with the results of the second performance test.
February 27, 2025 (current number of read/write cycles is updated automatically every hour)