Secure Digital (SD) cards are used in digital cameras, music players, smartphones, tablets, and even laptops. But not all SD cards are created equal. You’ll find different speed classes, physical sizes, and capacities. Some devices, like cameras, may require an SD card for their primary storage area. Other devices, like smartphones, tablets, and even computers, may offer the ability to use an SD card to increase storage or make it mobile. However, different devices require different types of SD cards. What does class mean on SD cards? Here are SD card classes explained, and the differences you’ll need to keep in mind when picking out the right SD card for your device.
SD Card Speed Class
SD card speed class is where things get complicated. SD cards come in four speed classes: class 10 SD card, class 6 SD card, class 4 SD card, and class 2 SD card. Class 2 SD cards are the slowest, suitable for standard definition video recording. Class 10 SD cards are the fastest, suitable for full HD video recording and HD still consecutive recording. The class number refers to the minimum write speeds in megabytes per second. For example, Class 2 = 2MB/s. Not all SD cards offer the same speeds. This matters for some tasks more than others. If you’re a professional photographer taking photos in rapid succession on a DSLR camera and saving them in high-resolution RAW format, you’ll want the fastest SD card you can get so your camera can save them as quickly as possible. A fast SD card from Buydig.com is also important if you want to record high-resolution video and save it directly to the SD card. If you’re just taking a few photos or using an SD card to store some media files on your smartphone, the speed isn’t as important.
UHS Speed Class
The SD Association has two standards associated with speed: Speed Class and UHS Speed Class (Ultra High Speed). These two standards aren’t compatible. Be sure to use the standard appropriate for your recording device. There are also two UHS speed classes, u1 SD card and u3 SD card. They’re more expensive and are designed for professional use. u1 SD cards and u3 SD cards are designed for devices that support UHS. The SD card U rating is available in SD cards that feature the UHS-I bus-interface. That means the u1 SD card and u3 SD card have circuitry designed to read and write to memory at speeds up to 312 MB per second. UHS speed refers to the absolute top theoretical speed of each card, instead of the minimum speed indicated by the card class. It’s a good way to gauge burst shot speeds.
Video Speed Class
The SD Association also classifies cards by a video speed class standard, which currently ranges from V6 SD cards to V90 SD cards. For 4K, a V30 SD card v rating or more is ideal. Video Speed Class SD cards also deliver real-time multi-file recording and support the highest video resolutions available today including 4K, 8K, 3D and 360-degree video. The new Video Speed Class standard is part of the latest SD 5.0 protocol, which ensures guaranteed minimum performance levels just as the Speed Class and UHS Speed Class classifications do for the current crop of SDXC cards. The fastest SD card v rating options, V60 SD cards and V90 SD cards will support 8K resolution. While V6 SD cards, V10 SD cards and V30 SD cards capture high-definition and 4K resolution and guarantee minimum sequential write speeds of 6 MB/s, 10 MB/s and 30 MB/s respectively. All speed classes guarantee minimum video recording speeds to ensure smooth video playback, so actual recording performance may be even faster.
A1 vs A2 SD Card
Are you wondering what the A1 SD card rating and A2 SD card ratings are on some micro SD cards? More and more, memory cards are being used to extend the memory of devices that run apps. Devices like smartphones and mobile gaming consoles. The apps that run on these devices interact with memory space differently. Rather than a stream of sequential data, they want to write a lot of small chunks of data wherever there’s space available. That’s known as random read/write. A card that’s fast for sequential reading and writing isn’t necessarily fast for random reading and writing. So just because a card might be able to record very high bitrate 4K or even 8K video doesn’t necessarily mean that it’s going to be a good fit for the different kind of use that applications might need. As a result, there’s a new rating system specifically to categorize suitability for SD and microSD cards in application-heavy uses. It’s known as the Application Performance Class Specification, and it’s written in the form of A1 or A2. What is the Difference between A1 and A2 Class in microSD and SD cards? The A1 SD card conforms to SD Physical 5.1 specification. Apart from helping you store a wide range of data including maps, pictures, videos, music, dictionary, and documents, the A1 SD card simplifies the task of editing and updating. The A2 SD card conforms to SD Physical 6.0 specification. The A2 SD card standard makes the cards run fast and at a higher performance level when compared to the A1 SD card. The standard makes use of functions like Command Queuing and cache with read speeds are over 2.7 times higher, and write speeds are four times faster, the A2 SD card would offer you an excellent upper hand over the A1 SD card.
While we have different ratings like class 2 to class 10, U1 and U3 and then V30 and V60 – neither of them replaces one another. The class rating, the UHS rating and the Video rating run parallel to each other. So, you’d find a microSD card or an SD card that comes with both A2 and V30 scores. When buying an SD card, you’ll need to buy the right speed class, size, and capacity for your needs. Be sure to check what your device supports and consider what speed and capacity you’ll actually need.
SD card for 4k video- This U3 card can write files as fast as 90 MB/s, with read speeds just a bit faster at 95 MB/s. That’s enough to capture 4K video as well as RAW bursts of photos. Even in the SD slot of a pro-level, 45-megapixel Nikon D850, it doesn’t have a problem keeping up with the big files that the camera captures.
Fastest micro SD card- Why settle for double-digit speeds when you can get triple? While the speeds of the fastest micro SD card are more than enough for most photographers, the Sony SF-G Tough series from Buydig.com hits write speeds of up to 299 MB/s, which is good for even 8K video thanks to a V90 video speed class.
SD card for 1080p- The 40 MB/s write speed on this ScanDisk 32 GB Extreme SD card is more than enough for hobbyists.
The safest way to make sure you buy the correct SD card is to first consult your product’s user guide or specifications.