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class4/class10/UHS-1/UHS-3 SD card speed level difference

Time: 2019-12-05 10:27:51

Author: 深圳业恒电子有限公司


The actual transmission speed of different SD memory card manufacturers and brands is very different. For video recording, a very high and stable minimum write speed is required. Therefore, various memory cards with different write speeds make it difficult for people to decide which card to choose to play smoothly. Therefore, the SD Association defines the speed level specification with two speed symbols to help consumers choose the required performance through reading and writing symbols. According to the development of SD bus, the two speed symbols are:

"Speed level" and "UHS speed level" represent the minimum write performance, which can ensure that dynamic content records such as video can be stored smoothly in a stable speed. This is very important for cameras, video recorders and other equipment with video recording function.

The speed level is designed with the lowest writing effect to record the film. The SD association has defined four speed levels: 2, 4, 6 and 10.

The UHS speed class is only applicable to UHS * * products. The UHS speed levels defined by the SD association are UHS speed levels 1 and 3.


There is no corresponding relationship between speed level and UHS speed level.

UHS is the abbreviation of ultra high speed, which is the type of memory card with the fastest speed level effect. It can define the bus interface to 312mb / s at most to show the better effect of the device. It is compatible with SDXC, SDHC memory cards and their devices.

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