Choosing The Best SD Card For Your Device

When is comes to storage on your device, sometimes the built in storage just isn’t enough. This is where adding an SD card can really extend the useability of your device. Unless you are unfortunate enough to own an iPad or iPhone, most devices will accept an SD card allowing you to boost your storage capacity significantly.

But when it comes to choosing the right SD card for your usage/device, things can get a little confusing. Today we aim to clear this up a little and help you to choose what is best for you.

Most phones these days use Micro SD cards, so that’s what we are discussing here. But the following guidelines generally apply for all SD cards.


SDHC stands for Secure Digital High Capacity and SDXC stands for Secure Digital Extended Capacity. The only real difference is the range of data that they can store. You’ll find that SDHC Micro SD cards range from 2GB to 32GB in size, while SDXC Micro SD cards can range from 32GB up to 2TB in size. Fortunately if you own one of the current BlackBerry phones, they will support up to 2TB, although the biggest Micro SD card we’ve seen so far is 512GB.

Class and UHS ratings

The Class rating of a Micro SD card refers to its minimum transfer speed. UHS stands for Ultra High Speed. Most Micro SD cards are a lot faster than the minimum speed.  For example, a Class 10 card may offer 95 MB/s, and UHS cards can go up to 312 MB/s. Here’s a guide for the minimum speeds for different classes:

Class                               Minimum Speed

2                                                   2MB/s

4                                                   4MB/s

6                                                   6MB/s

8                                                   8MB/s

10                                                 10MB/s

UHS 1                                             10MB/s

UHS 3                                             30MB/s

Application Performance Class

The SD Association also recently released a new standard, called App Performance Class, which is used to highlight Micro SD cards that are suitable for use in smartphones and tablets. The A1 rating means that the card can manage random read input-output access per second (IOPS) of 1,500 and write IOPS of 500. This is best for quickly opening apps and handling tasks. These new A1 cards are recommended if you intend to format your card as internal storage, allowing you to store apps on them. Brad explains the advantages and disadvantages of mounting your SD card as internal storage here HERE.

SD card

How to choose a Micro SD card

You’re obviously going to want the highest speed, highest capacity Micro SD card you can get, for the lowest price. It is advised to take into account the brand reputation and the reported performance and reliability. Check out the warranty terms, some offer a Lifetime warranty. If you’re buying from an online store such as Amazon or eBay then read some customer reviews.

You also need to be aware of “fake” SD cards, because they’re very common. If the price is too good to be true, there’s generally a reason for that so again, check out feedback/reviews and only buy from a reputable seller. It’s simply not worth the risk to lose your precious data.  It is also advised to stick with a reputable, well known brand such as Samsung, Lexar, SanDisk, Toshiba, and Kingston.

If your device is capable of recording in 4k video, you are going to want an SD card with a  UHS 3 rating. If you are recording video in 1080p only then a UHS 1 or Class 10 will be fine as long as the write speeds are respectable. Again, choose the best card that your budget will allow, with the highest rating/speeds.

Most Micro SD cards these days come with a card adapter to be able to access your data from a PC, so keep an eye out if your choice includes a card adapter.

Here are some links to popular SD cards as found on Amazon:

SanDisk Ultra 200GB available in 8GB, 16GB, 32GB, 64GB, 128GB, 200GB and 256GB. Performance/speed: Up to 90MB/s read speed, write speed lower)   Class 10 for Full HD video (1920×1080)

SanDisk Extreme UHS 3 available in 16GB, 32GB, 64GB and 128GB. Read speeds of up to 90MB/s; write speeds of up to 60MB,  UHS speed Class 3 (U3), video speed Class 30 (V30) and Class 10 for 4K UHD and full HD video, Lifetime Warranty

Samsung SDXC 64GB Class 10 UHS-1 Up to 80MB/s Transfer Speed with Class 10 and UHS-1 compatibility, Ideal for Full HD Video recording and high resolution pictures, Reliability Built to Last – Water, Temperature, X-ray and Magnetic Proof


Lexar Micro SDXC UHS-II/U3 available in 32GB, 64GB and 128GB, High-speed performance-leverages UHS-II technology (U3) for a read transfer speed up to 1000x (150MB/s), Designed for high-speed capture of high-quality images and extended lengths of 1080p full-HD, 3D, and 4K video, Includes lifetime copy of downloadable Image Rescue software