SD Speed Class/UHS Speed Class/Video Speed Class
Greater Performance Choices
There are three kinds of Speed Classes, “Speed Class”, “UHS Speed Class” and “Video Speed Class.”
As a characteristic of flash memory, actual transfer speed varies. Variable speeds are difficult to reliably record streaming content such as video because it requires a constant writing speed. All Speed Classes provide the constant speed necessary for video recording by designating a minimum writing performance so that minimum and constant speed could be achieved for camcorders, video recorders and other devices with video recording capabilities under the conditional write operation specified in the standard.
SD Standard | SDHC Standard | SDXC Standard | SDUC Standard | ||
Capacity | up to 2GB | more than 2GB
up to 32GB |
more than 32GB
up to 2TB |
more than 2TB
up to 128TB |
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File System | FAT 12, 16 | FAT 32 | exFAT | exFAT | |
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Form Factor Size | SD | 32 x 24 x 2.1 mm | |||
microSD | 11 x 15 x 1.0 mm | ||||
Speed Classes |
Normal Speed mode |
C2, C4, C6 | |||
High Speed mode |
C2, C4, C6, C10,
V6, V10 |
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UHS-I
mode |
— | C2, C4, C6, C10
U1, U3 V6, V10, V30 |
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UHS-II
mode |
— | C4, C6, C10
U1, U3 V6, V10, V30, V60, V90 |
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UHS-III
mode |
— | C4, C6, C10
U1, U3 V6, V10, V30, V60, V90 |
SD Speed Class
Video Format