XrayDisk High Endurance 32GB

  • Obtained from: AliExpress
  • Price paid: $3.70
  • Advertised size: 32GB
  • Logical capacity: 31,275,876,352 bytes
  • Physical capacity: 31,275,876,352 bytes
  • Fake/skimpy flash: Skimpy (2.26% skimp)
  • Protected area: 134,217,728 bytes
  • Adjusted skimp: 1.84%
  • Speed class markings: Class 10, U1, A1
  • CID data:
    • Manufacturer ID: 0x6f
    • OEM ID: 0x0303
    • Product name: 0x5344414243 (ASCII: SDABC)
    • Product revision: 0x10
Card #123Average
Serial number0xaa0008a10xaa0008da0xaa0008d3N/A
Manufacture dateMay 2023May 2023May 2023N/A
Sequential read speed (MB/sec)58.2180.7166.9468.62
Sequential write speed (MB/sec)47.9645.7933.1242.29
Random read speed (IOPS/sec)1,429.201,451.991,454.281,445.16
Random write speed (IOPS/sec)112.60394.5910.76172.65
Read/write cycles to first error1226727
Read/write cycles to complete failureNot yet determinedNot yet determinedNot yet determinedNot yet determined
Total days to complete failureNot yet determinedNot yet determinedNot yet determinedNot yet determined
Card reader usedSmartQ SingleJJS CR-UTC4ACJJS CR-UTC4ACN/A
Package frontN/A
Package backN/A
Card frontN/A
Card backN/A

Discussion

This is an off-brand product that came up early in my AliExpress searches, and I think the “High Endurance” part of the name may have been what inspired me to obtain the SanDisk High Endurance and Samsung PRO Endurance to have some name-brand samples to compare it to.

Performance-wise, sequential read and random read speeds were close to average. Sequential write speeds were above average, while random write speeds were below average. Compared to the other off-brand cards I tested, however, sequential speeds and random read speeds were above average, while random write speeds were below average. Performance on all three cards was good enough to qualify for the Class 10 and U1 markings that they carried, but no single card scored well enough to qualify for the A1 marking. Given that all three cards got close to the 1,500 IOPS/sec threshold for random read operations, and sample #2 got somewhat close to the 500 IOPS/sec threshold for random write operations, it’s possible that they would have performed better under proper testing conditions.

I wish measurements had been clustered closer together — but the fact that they’re not could indicate inconsistencies with how these cards were manufactured.

What really disappointed me, however, was endurance: all three of these cards only managed to go for a few read/write cycles before hitting their first error. The fact that this happened with all three cards and that the data points are so close together points to a possible quality control issue (although who am I kidding, these cards didn’t go through any quality control). On the bright side, these cards did display some ability to self-heal, as all three cards stopped displaying errors after round 136. However, endurance tests are still ongoing. As of the time of this writing:

  • Sample #1 experienced a 1,258-sector wide error during round 13. I don’t know the nature of the error, because the version of the program I was using at the time didn’t log this information. It has survived 8,160 read/write cycles so far. (In the interests of full disclosure, I will say that there were more errors after round 136, but those were attributable to problems with the portions of my code that handles device disconnects/reconnects. Once those problems were fixed, the card stopped experiencing errors.)
  • Sample #2 experienced a series of bit flip errors affecting 8 sectors starting in round 3; it has survived 3,822 read/write cycles total so far and has not experienced any further issues since then.
  • Sample #3 experienced a series of bit flip errors affecting 18 sectors during round 68, and a couple more data verification errors during rounds 761, 831, and 1,148. (Although given that the actual data read back during round 1,148 was right shifted from the expected data by exactly 4 bits, and the device experienced an error immediately afterwards that required it to be reset, I think it’s reasonable to assume that either the card or the reader missed a clock cycle while returning data.) It has survived 2,806 read/write cycles total so far.

June 9, 2024

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