Suitability of Flash Media for the Long-Term Storage of Information

Abstract

Flash storage media such as memory cards and USB flash drives are now commonly used to transfer and store information. However, little is known about the long-term stability of this type of media and this is a concern for archives and other institutions as they begin to receive content stored on these devices. In this study, the stabilities of a variety of different flash media were examined. The evaluation was performed by using accelerated ageing at 85 °C and 85 % relative humidity (RH) and 125 °C for ageing intervals up to 2000 hours. Measurements were also performed on samples previously subjected to accelerated ageing and then naturally aged for five years to verify the results from the accelerated ageing experiments. Overall, the stability of flash media was very good. For many of the samples, no read errors were encountered after accelerated or natural ageing. However, for several of the high capacity flash card samples and USB flash drives, significant decreases in read speed were noted. This can be problematic because it will eventually lead to read errors. It was established that for the USB samples this instability was likely attributed to the use of the less stable TLC (triple-level cell) memory chip.