SD Card FAQs: Everything You Need to Know to Save Space and Store More Media

“Security Digital” (SD) Cards live inside your portable devices (e.g. smartphones, tablets, cameras), and securely store their data. The more you want to do with them, the more there is to know, so here is a guide to questions you may have about SD specifications, features and proper maintenance.

What do the “Families”, Sizes and Speeds of SD Cards mean?

An SD Card’s “family” indicates its data storage capacity, from SDSC (Standard Capacity: up to 2 GBs of space) to SDXCs (eXtended Capacity: up to 2 terabytes). SDIOs are a family with unique input, output and memory functions built-in, such as internet service and GPS. They come in three sizes: standard, mini and micro, which are each a few inches but have similar capabilities. Each Card has a Speed Class which indicates how fast it can read and write information to and from the Card, ranging from 2 MB/s to 321MB/s.

How will I know if my Card is compatible with my device?

Many families, sizes and speeds are available for different purposes and devices, and while adapters exist to provide some compatibility you should always check online first.

What are some of the unique benefits of SD Cards?

SD Cards have a high data transfer rate and low battery usage. Some provide protection against water, shock and magnetism as well. You can save apps to your SD Card rather than your memory on some newer devices (e.g. Android 4 and above) by navigating to “settings”, “applications” and selecting an option called “move to external memory” or something similar. Browse manufacturer’s websites or large online retailers like this site to survey the whole range.

What data protection do SD cards offer?

SD cards can be digitally locked with a password and physically locked with a switch on the card, enabling “write-protected” mode to stop your files being edited until someone switches the lock off. Many also contain DRM copy protection. If your card gets stolen your emails and text will be safe as they are contained in your device’s internal memory, but audio, images, video and app data will be vulnerable: so keep it safe!

Can I recover files I accidently deleted from my SD card?

Unless you have another backup this is tricky. If you’re quick enough, have the right device and are lucky, you can sometimes recover them with a tool like Recuva.

How else can I backup my data?

You could use another external device like a hard drive, set up a full system backup locally on your PC, or use an online cloud service like Carbonite or CrashPlan, which charge ongoing fees for online storage space which is safe from data corruption or theft.

How do I avoid damage?

Handle the SD Card carefully and avoid grime or scratches.

How do I identity errors?

Lower quality recordings are evidence of older cards of lower Speed Class. If you have data corruption you may notice error messages, missing photos or folders and not being able to open your files.

How do I use data recovery software?

Recovery software can be downloaded for free over the internet and give you options between partial (often called “quick”) and full scans, which look to salvage all your files rather than only one subfolder or type of file. They then present you with a list of files to recover. If the damage is severe enough or you leave it too late, some files may be damaged or unrecoverable with even the best software.

Got further questions?  Check out the SD Association FAQ.

Isabel Ward is tech savvy when it comes to computers. She’s a photographer who also dabbles in graphic design and relies on her computer for working. She shares some of her tech knowledge online with her articles.