A German data recovery firm has warned of an increase in low-quality flash storage devices on the market, seemingly a result of components that fail quality control checks being repurposed in lower-capacity devices — with their original markings obliterated to mask the trick.
"Over the past year, we have found alarmingly low-quality memory chips with reduced capacity and erased manufacturer logos on the chips when opening defective USB flash drives," writes CBL Data Recovery's Conrad Heinicke of the company's discovery, in translation. "Obviously discarded and unrecognizable microSD cards are soldered to a USB stick and managed though an external controller instead of the microSD's internal controller. "These USB sticks were predominantly doubtful quality promotional gifts, but also included branded products."
The discovery of USB drives using failed microSD card components in only part of the reason Heinicke warns that "one should not rely too much on the reliability of flash storage." The company also accuses the move from single-level cell (SLC) flash, in which each memory cell could store a single bit of data, to multi-level cell (MLC) as being responsible for dropping the reliability of flash memory components even as it increased their storage capacity.
"Even in high-quality memory chips, the effort that must be done by manufacturers for error correction in the controller is enormous," Heinicke writes. "It is not surprising that data loss is common with the USB sticks in which discarded chips are installed. Flash memory is practical, but you should be aware that they can lose data, for example, when stored for longer periods of time. These unknown chips with erased manufacturer logo do not make data recovery easier for us. Fortunately, we have succeeded in improving our tools by using AI [Artificial Intelligence] and reducing the effort of software development to create flash memory recovery algorithms."
For those looking to avoid storage devices built around previously-discarded components, sticking to brand-name hardware is advised — though not always a guarantee. CBL offers some other tips, too, including storing flash devices at lower temperatures to slow bit-rot, reading their contents once or twice a year to give the error correction algorithms a chance to catch and fix minor errors early enough, and to avoid filling storage devices to their limit to leave room for wear-leveling algorithms to work.
CBL's full write-up is available, in German, on the company website.