Everything you need to know about SD card Markings

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While buying an SD card, we only look at the storage capacity, for instance, 8GB SD card costs more than 4GB SD card. We often overlook other aspects of the SD cards, which could play a bigger role during a day to day performance. With so many SD cards in the market, it’s important to understand which SD memory card works best with your device. Here are the top six markings of the SD cards you should know before you buy one:

SD Card

1. Storage:
This is the most common thing about SD cards. This indicates the total storage of the SD card. It can range from 1GB to upto 512 GB. More the storage, more you be able to store photos and videos.

2. Write Protect Logo:
The logo represents if the button on the left side is plugged in downwards or upwards.

  • If the button is plugged upwards, you can erase and write all your files and folders.
  • If the button is plugged downwards, erasing or writing the data is impossible.

3. Read Speed

SD cardsIt represents the maximum read speed that the SD card can spit out. It is based on the manufacturer’s internal testing. Usually, the write Speed of the SD card is typically lower than the read speed. The circle marking in this photo shows the read speed of the SD card. It says 95MB/s, but usually, it is much lower in real time usage.

4. Formats
There are currently three SD factors:

card shape

Secure Digital Standard Capacity (SDSC or SD): FAT 12/16 file system max storage- 2GB
Secure Digital High Capacity (SDHC or MicroSD): FAT32 file system max storage- 32GB
Secure Digital Extreme Capacity (SDXC) exFAT file system max storage- 2TB

5. Speed Class
Speed class denotes the minimum write speed of the SD card. There are currently 4 Speed Classes that is defined by the SD Association –Class 2, Class 4, Class 6, and Class 10.

As the name suggests, Class 2 means minimum write is speed is 2MB/s, Class 4 means 4MB/s and so on. Usually, Class 2 SD card is used for video recording, Class 4 and Class 6 SD card is used for Full HD video recording and Class 10 SD card is used for HD and Full HD video still consecutive recording.

UHS Speed Class was introduced in 2009 by the SD Association and is designed for SDHC and SDXC memory cards. UHS memory cards have a full higher potential of recording real-time broadcasts, capturing large-size HD videos and extremely high-quality professional HD.

Class 2 2MB/s
Class 4 4MB/s
Class 6 6MB/s
Class 10 10MB/s
UHS Speed Class 1 (U1) 10MB/s
 UHS Speed Class 3 (U3) 30MB/s
Video Speed Class 6 (V6) 6MB/s
Video Speed Class 10 (V10) 10MB/s
Video Speed Class 30 (V30) 30MB/s
Video Speed Class 60 (V60) 60MB/s
Video Speed Class 90 (V90) 90MB/s