Reports that low-quality NAND flash memory is on the market and the quality of USB memory and microSD cards is declining

CBL, a German data recovery company, has announced the results of a survey showing that the quality of microSD cards and USB memory is declining. The reason for this is that there are an increasing number of cases in which NAND flash memory, which was discarded by manufacturers during quality control, is being diverted and reused.

Unzuverlässige Flash-Speicher - CBL Datenrettung

Report reveals decline in quality of USB sticks and microSD Cards | TechSpot

According to CBL, there are an increasing number of cases where NAND flash memory that has failed quality control is being resold and reused by highly reliable manufacturers such as Hynix, Samsung, and SanDisk. Although such NAND flash memory can be used, it seems that the memory storage capacity has decreased from the beginning.

Conrad Heinicke, Managing Director of CBL, said: ``In 2023, when we disassembled defective USB drives, we found a surprising number of inferior NAND flash drives with reduced capacity and manufacturer logos removed. ” is reported.

Below is a photo of the USB memory and the NAND flash memory installed in it. The NAND flash memory has polishing marks and all labels have been removed.

In addition, there were cases in which microSD cards that had clearly been discarded and were unrecognizable were soldered to USB memory, and were managed by an external controller on the USB memory's board rather than the microSD card's internal controller.

According to Mr. Heinicke, most of the inferior USB memory investigated by CBL were promotional items such as those included with products or distributed free of charge by companies at conferences. However, it seems that there were also brand-name USB flash drives that were sold on the general market.

Additionally, CBL claims that inexpensive NAND flash memory is less reliable due to its prioritization of storage density. NAND flash originally consisted of single-level cells (SLCs) that could store only one bit. Therefore, there was no problem as long as the controller could distinguish between the two voltage levels. However, the mainstream of inexpensive NAND flash memory is quad-level cell (QLC), which can store 4 bits/16 values in one cell. CBL claims that while QLC increases storage density, it reduces writability and storage capacity, which means durability and retention.

Inexpensive NAND flash memory reduces the maximum number of possible read/write cycles, and older NAND flash memory is at increased risk of becoming unable to read charge differences as the insulating layer deteriorates over time. Mr. Heinicke said, ``Even if data is lost to an unknown NAND flash memory with the manufacturer's logo removed, it is not easy to recover it.'' I'm warning you that you shouldn't.

in Hardware, Posted by log1i_yk