MicroSD cards are now the dominant storage expansion medium in today's devices. Officially known as micro secure digital cards, these can offer as much as 128GB of additional space, depending on the model or brand. Some have even higher write speeds to keep up with the high capacities offered.
Given the different kinds of microSD cards, how does one choose the right one for their device? Let's take a look at a few important terms to know when buying one.
MicroSD Cards are now classified according to three main types according to capacity. These are the following:
SD - These are the regular cards with a maximum capacity of 2GB.
SDHC - Otherwise known as the "high capacity," these can store up to at least 32GB.
SDXC - Known as the Secure Digital eXtra Capacity cards, these can store up to 2TB worth of data. This capacity makes it ideal for use in devices like video cameras and high-end phones like the Samsung Galaxy S7.
These three kinds may or may not be compatible with your device. As a general rule, devices that can use microSD Cards are backwards compatible. For example, an SDXC-compatible device can use SDHC and SD cards. On the other hand, an SDHC-compatible device can only use the older SDHC and SD cards.
As with the capacity classes, microSD cards are also classified according to speed, according to the SD Association. These speed classifications refer to the absolute minimum sustained write speeds. It’s important to note that these are the minimum, so it’s entirely possible a card can achieve faster speeds depending on the type of USB connection you have. As a rule of thumb, the cards are labelled according to the speeds they can write with.
Speed Class – These can come in the Default Speed and High Speed modes (DS and HS, respectively) and can be marked with a Class 2, 4, 6 or 10 label. Class 2 cards start with 2MB per second, while Class 10 cards—the highest—can range up to 10MB per second.
Ultra High Speed (UHS) Class – The UHS Speed Class is labeled with either a 1 or 3 inside of a bucket U symbol for higher capacity SD Cards. These can come in speeds starting from 10MB per second and can go up to 30MB per second. As a rule of thumb, 4K-capable camcorders will usually require at least a U3 rated SD card.
Video Speed Class (VSC) – The newest class of SD Cards, which come in 5 speed labels: V6 for 6MB per second, V10 for 10MB, V30 for 30MB, V60 for 60MB, and V90 for 90MB per second. These cards are optimized for use on video or action cameras like the GoPro.
Usually, the VSC cards are ideal for HD videos for up to 8K due to their fast writing speeds and high capacities.
For other cameras like the Sony HDR-AS50 Action Camera, you can only use the ones made exclusively by Sony to ensure maximum compatibility. These include the XQD G Series Memory Card for faster speeds and clearer quality images.
It's also important to note that the Speed Class, UHS Speed Class, and Video Speed Class have no compatibility issues with card capacities. For example, even an SDHC card like the 32GB SanDisk Extreme Plus can be classified as a U1 card. This allows it to be used on cameras or even smartphones that have high-end cameras.
How do you choose the right one?
There are just two steps to take when choosing your next microSD Card. The first step is to check the manufacturer’s manual or the packaging of your device. This is to see the types of microSD card your gadget can support. Some smartphones like the Sony Xperia Z5 may support SDXC Cards, while the Samsung Galaxy J1 can only use SDHC or SD Cards.
Once you have this information, the next thing to check is the read and write speeds of the card you want to get. If you're not the type who needs to record HD videos in 4K, a Class 6 will usually suffice.
A faster rated card could still help if you're looking to expand the storage in a smartphone or tablet, as this can make the device more responsive. As an added benefit, faster types like a Class 10 card can allow you to take faster photos in burst mode and transfer files quicker. Depending on your choices, an extra investment might be worth the price.
Now that you know the different types of microSD cards, you’ll never make the mistake of getting one that’s too slow or small for your needs.