Taking a Closer Look at NAND Flash Data Retention Time
When choosing a NAND flash storage device, many OEMs focus on the number of program and erase cycles that a device is capable of providing, but it is also important to consider a different, though somewhat linked, factor: data retention rates. NAND flash data retention time lets you know how long stored data can survive on a NAND flash device, even if the device has not been used recently. For industrial grade users, this information is particularly important, as they need NAND flash data retention times to be sufficient even in extreme conditions. Here is what you need to know about NAND flash data retention.
NAND Flash Endurance vs. NAND Flash Data Retention Time
Endurance and data retention are often confused, but they are two different concepts. Endurance refers to the number of program and erase cycles (or P/E cycles) a flash memory device can complete in its lifespan. There are several factors that influence NAND flash endurance, including the type of flash memory and the operations it performs in the host device. As a very general guideline, many MLC NAND flash devices have endurance rates of about 10,000 P/E cycles, while SLC NAND flash may be able to perform around 100,000 P/E cycles. These are broad averages, and there are several different device-specific factors that could influence the endurance of any device.
NAND flash data retention times refer to how long stored data will be saved on the storage device. As a guideline, most manufacturers say that their flash devices have data retention times of about 10 years, but as with endurance, there are many different factors that can impact the actual data retention of the storage device in question.
Factors That Influence NAND Flash Data Storage Times
The reason why the number of P/E cycles is linked to data retention time is that data retention becomes more of an issue when the maximum endurance lifespan of a device is being reached. As endurance begins to wane, so does NAND flash data retention time.
Temperature is another major factor. Both extreme high and low temperatures affect data retention rates. For this reason, it is important for industrial users who need storage for rugged conditions to choose an industrial grade storage device. Industrial grade devices are rated for extreme conditions, reducing the risk of data retention issues due to temperature extremes.
Delkin’s customer team can help you evaluate the endurance and data retention rates of different NAND flash storage options and can provide customization as needed for your device. Contact us today with your questions.