New A 1 and A 2 speed classes for SD cards

What do they mean and why you would want them.

With the rapid advancement in smartphone technology, a new SD card standard is born – the A1 and A2 speed class offers app performance, promising faster load times when installing or opening apps directly from your microSD card. Here’s the down low.

The dawn of smartphone-oriented SD cards

SD Association’s new A1 and A2 speed classes are designed for Android smartphone users who absolutely need to install apps onto their microSD card. The creators of this new standard have prompted aftermarket memory card makers to take on A1 and A2 into their SD card portfolio. In turn, the brands have taken it upon themselves to market A1 and A2 speed classes as a preferred choice for smartphone storage over other storage scenarios.

Why are there SD cards for faster app loading times?

If you’ve ever tried to format an older microSD card as internal storage on your compatible Android phone, you might have encountered a pop-up message saying that your regular microSD card is too slow, and its performance would suffer. That’s a huge inconvenience when your smartphone doesn’t have sufficient built-in storage space for modern apps that continue to grow larger and larger.

So what if I have A1 or A2 microSD cards?

The new standard works well for loading assets when you start an app. Executable files and execution will still rely on your phone’s RAM and storage. A good example of apps benefiting from A1 would be games with negligible file sizes on the app store, but with large asset files that start downloading after you launch the app for the first time. Also, whenever you start a graphically-heavy game, having it on the A1 microSD card may help reduce loading times.

Who would benefit most from microSD cards with A1 speed class?

Broadly speaking, users who have the habit of installing game apps onto the memory card will see reduced loading times, especially at the app’s startup.

The new speed categories take advantage of Android’s Adoptable Storage Device support, so smartphones running Android 6.0 OS (Marshmallow) and Android 7.0 OS (Nougat) are compatible with such microSD cards.

According to Hon Wai Cheah, Director of Product Marketing Management, APAC at SanDisk, the effects are more pronounced on mid-range and entry-level smartphones, since their internal storage format usually isn’t as fast as newer storage technologies found on flagship phones, such as UFS 2.0. On higher end smartphones with newer storage technologies, an A1capable microSD card won’t beat their loading times, but it serves to complement the phones’ performance.

How can I tell if my microSD card has A1 or A2 standards?

The memory card needs to meet the following minimum speed specifications to qualify for an A1 or A2 pictograph on its packaging:

To qualify for the A1 application performance class standard (also known as Class 1), SD Association requires the memory card to have a Minimum Random Read of 1,500 IOPS (input/output operations per second), and a Minimum Random Write of 500 IOPS, along with a Minimum Sustained Sequential Write speed of 10MB/s (10-megabytes per second).

The spec requirements for the A2 standard are higher, with a Minimum Random Read of 4,000 IOPS, Minimum Random Write of 2,000 IOPS, and Minimum Sustained Sequential Write of 10MB/s. While it serves the same purpose, memory cards with the A2 logo (also known as Class 2) offer IOPS speeds faster than A1’s - if they meet the standard’s demands.

Isn’t that lower than UHS-II’s minimum read/write speeds? How is this an upgrade?

The different use cases between UHS-I1 and UHS-II versus A1 and A2 are what make the different standards unique and important to their respective fields.

Your UHS-I and UHS-II speed classes are designed for swift reading and writing from cameras to SD card. The 156MB/s full duplex bus speed for UHS-II is built to handle rapid data entering the card in a short amount of time – this is more prominent if you’re doing burst shots on your DSLR camera. A1 and A2 speed class cards, on the other hand, are made for swift load times – hence why the latter two have IOPS requirements.