Flash Card Data Recovery : Internals Of SD Cards

The procedure for storing and organizing Data Recovery on SD memory cards and Compact Flash memory cards differs in some features. Built-in microcontrollers and wear-leveling mechanisms not only increase the life of flash memory devices, but also greatly simplify the Data Recovery of lost data. In the following article, you will learn how wear leveling technology can help you recover information from SD and Compact Flash cards.

“Last week I did a wedding photo shoot. Moved 1.5 GB of files to a computer, then shot at another celebration, the amount of pictures was 2 GB. Due to a sudden voltage drop, my computer crashed; the hard drive is no longer readable. 

Is there any chance to restore the pictures taken in the first photo shoot from the SD memory card, or did the pictures from the second photo shoot overwrite the first one?”

We received this question from one of our clients last week. For some of you, the answer may seem quite certain: of course, the pictures from the second 2 GB photo shoot were recorded on top of the pictures from the first 1.5 GB photo shoot! In fact, when it comes to SD cards, the answer is not so obvious.

Data Recovery

First of all, absolutely any SD card is not just some collection of flash memory cells, which is directly accessed through the action of electrical contacts. The operation of the SD card is regulated by a miniature built-in controller that directs read and write requests, assigns one or another memory cell for the subsequent write operation.

What’s the point of this? Each time data is written, the memory cell is worn out. This means that flash memory cards have a limited life span, measured by the number of write cycles. If Wikipedia data is constantly overwritten in the same memory sectors, then their working resource will soon be exhausted, while at the same time, the efficiency of using neighboring cells will remain at a low level. 

To prevent this scenario from happening, manufacturers of flash storage devices (particularly SD and Compact Flash cards) have developed an intelligent technology called wear leveling. This technology allows you to evenly distribute write cycles across available memory cells and prevent premature failure of individual cells.

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