Recording Media SD/SDHC/SDXC

Types and standards of inexpensive Recording Media.

●    The SD (Secure Digital) card has been available since 2000, it is now available in a range of formats including SD, miniSD and microSD,
●    Caddy-style adapters are available to enable the use of SD media in CF, or SxS device
●    The media has a lifetime of 100,000 to 1,000,000 write cycles

The Secure Digital card has a variety of different standards that have evolved over time to support the increase in individual file sizes.

SD standard

●    Supports upto 2GB files in FAT16 format

SDHC standard

●    Supports upto 32GB in FAT32 format
●    Not backwards compatible
●    This standard introduced power classes : class 2, 4, 6, 10. These clases denote the minimum data transfer rate in MB/s. E.g Class 10 = 10MB/s

SDXC standard

●    Supports memory sizes up to 2TB, although currently SDXC cards of a maximum of 512GB are available in the market.
●    The introduction of new classes of UHS, UHS II and UHS III are the bus speeds of the memory card.
●    UHS I and UHS II describe the bus speed as 104 MB/s or 312 MB/s respectively. UHS III introduced a bus speed of 624MB/s
●    The UHS Class system has introduced two different class ratings – U and V.
●    U1 supports 10MB/s and U3 supports 30MB/s
●    The V class was introduced to indicate the Video Speed Class. Like the other classes the number after the V, e.g. V6, indicates the speed. V6= 6MB/s
●    The V-class cards are available in V6, V10, V30, V60, V90.
●    V60 and V90 are rated for 8K UHD recording at 60 and 120fps.