Which Class of SD Cards is Better?

which class of cards is better

by Alex Gustman

Updated: April 28, 2021

Memory card manufacturers usually specify the class and speed of the drive in detail on the media, giving a general idea of the overall capabilities. In this article, you will learn which class of SD cards is better, what the difference is, and how to choose a memory card.

How do I choose a memory card?

When choosing a drive, you need to consider the usage scenarios:

  • Periodic video recording or playback.
  • Storage of various information.
  • Launch applications.
  • Continuous video recording.
  • Take photos and videos in a digital camera or camera.

The most balanced solution for different usage scenarios is a card with a speed class of 10. Such a drive will cope with any tasks that are not demanding for the type of memory and / or speed/mode of operation.

16 gigabyte memory card

Drives of the Endurance or High Endurance class are characterized by an increased service life. Thanks to the use of MLC memory, these drives are suitable for regular recording in surveillance cameras, car recorders and baby monitors. These drives are also suitable for frequent photo and video shooting in conventional video cameras/cameras.

For sequential video recording, the class card will do better Video Speed Class or VSC for short. These cards are suitable for recording video in high resolution-4K and 8K.

Application Performance Class cards, or APC for short, are designed to run games and programs directly from the drive.

Industrial cards are designed for use in difficult conditions: high humidity, high or low temperature, the presence of radio or magnetic radiation.

What do the different classes of SD cards mean?

The class means the minimum write speed to the SD card. The class is denoted by a number in the letter “C”, with the corresponding write speed in MB/s. There are 5 classifications used:

  • Without class. The class is not specified on the map, the write speed is up to 2 MB.
  • С2. Class 2 with a write speed of at least 2 MB.
  • C4. Class 4 with a write speed of at least 4 MB.
  • C6. Class 6 with a speed of 6 MB or higher.
  • C10. Class 10 – 10 MB and higher.
memory card with durable memory

In some drives, the class is specified as a multiplier with the exact designation of the write speed, where 1 multiplier of 1x is equal to 150 KB/s. Accordingly, the multiplier of 633x is 95 MB/s. The multiplier notation is often used in maps where the write speed is higher than Class 10.

The write speed of some maps often exceeds the specified class or exceeds it only in certain tasks. For example, the speed of the C6 card can reach 9 MB or, conversely, not exceed 6 MB. If the write speed is less than the specified value, such a drive is defective or fake.

What is the difference between Class 4 and Class 10 SD cards?

The difference in the minimum write speed to the memory card is 4 and 10 MB, respectively, also in the read speed corresponding to or exceeding the write speed. Therefore, the speed of the Class 10 card is at least 2.5 times higher than the Class 4 card.

Is UHS 1 the same as Class 10?

UHS is a data exchange protocol that helps speed up the writing and reading of the drive. Usually, the UHS 1 logo marks cards with a write speed of more than 10 MB.

According to the accepted standard, the minimum write speed of UHS 1 corresponds to the minimum write speed of Class 10. In practice, the write speed of cards with UHS 1 often reaches 25-30 MB and higher, and the read speed is 90 MB.

Kingston Memory Card Class 10

Which SD cards are the fastest?

The fastest cards are those that support the UHS II protocol. The write speed of some of these drives reaches 300 MB, for example, the SanDisk Extreme Pro series.


This article describes in detail which class of SD cards is better. Memory cards are versatile and suitable for any task. The exception is specific requirements for the type of memory, speed, or mode of operation. In this case, the best choice is a map that is focused on a specific task with the required write speed and volume.

What questions do you have? Leave messages in the comments below the article.

More about this

About the author 

Alex Gustman

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}