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About Speed

There are two types of expressions in speed. One is the maximum transfer speed, and the other is “SD Speed Class”

1. Maximum Speed

This means the maximum speed in write or read operations onto SD memory card.
(*The average performance of these operations is lower than the maximum speed and depends on the situation of the inner status of SD memory card.)
Higher speed cards have these benefits (maximum speed)

2. Speed Class (Guaranteed Minimum Speed)

Speed Class designates minimum writing performance. It was designed for streaming data recording.The "Speed Class", Class2, 4, 6 and 10 for the current Bus I/F and the "UHS Speed Class" Class 1 works under UHS-Ι Bus I/F. (The Speed Class and the UHS Speed Class are not compatible.)

Marks Operable under... Applications
Speed Class CLASS 2 Normal Bus I/F SD video recording
HD — Full HD video recording
High Speed Bus I/F Full HD video recording
HD still consecutive shooting
UHS Speed Class UHS-Ι Bus I/F For higher potential of recording real-time broadcasts and capturing large size HD videos

3. UHS-Ι Bus Interface and UHS Speed Class

UHS-Ι is the new standard for higher-speed bus interfaces defined by the SD Association as part of the SD Memory Card Specification Ver. 3.01, which provides up to 104 MB/s performance.

What the Marks Mean (UHS-Ι, SDHC Card)

Bus Mode Bus Speed Speed Class
UHS-I (Ultra High Speed) Up to 104 MB/s UHS Speed Class 1
(High Speed or Default Speed)
Up to 25 MB/s Speed Class 2, 4, 6, 10
(Higher Speed Class covers lower class performance.)