Secure Digital High-Capacity

Secure Digital, officially abbreviated as SD, is a

proprietary {{Short pages monitor logical sectors (smaller than 7.8 GB):

FAT32 File Allocation Table (FAT) is a file system developed for personal computers. Originally developed in 1977 for use on floppy disks, it was adapted for use on hard disks and other devices. It is often supported for compatibility reasons by ...

with partition type 0Bh and

EBPB 7.1 In computing, the BIOS parameter block, often shortened to BPB, is a data structure in the volume boot record (VBR) describing the physical layout of a data storage volume. On partitioned devices, such as hard disks, the BPB describes the volum ...

** Capacity of at least 16,450,560 logical sectors (larger than 7.8 GB):

with partition type 0Ch and

* For SDXC cards:

exFAT exFAT (Extensible File Allocation Table) is a file system introduced by Microsoft in 2006 and optimized for flash memory such as USB flash drives and SD cards. exFAT was proprietary until 28 August 2019, when Microsoft published its specificati ...

with partition type 07h Most consumer products that take an SD card expect that it is partitioned and formatted in this way. Universal support for FAT12, FAT16, FAT16B, and FAT32 allows the use of SDSC and SDHC cards on most host computers with a compatible SD reader, to present the user with the familiar method of named files in a hierarchical directory tree. On such SD cards, standard utility programs such as Mac OS X's "" or Windows' SCANDISK can be used to repair a corrupted filing system and sometimes recover deleted files.

Defragmentation In the maintenance of file systems, defragmentation is a process that reduces the degree of fragmentation. It does this by physically organizing the contents of the mass storage device used to store files into the smallest number of contigu ...

tools for FAT file systems may be used on such cards. The resulting consolidation of files may provide a marginal improvement in the time required to read or write the file, but not an improvement comparable to defragmentation of hard drives, where storing a file in multiple fragments requires additional physical, and relatively slow, movement of a drive head. Moreover, defragmentation performs writes to the SD card that count against the card's rated lifespan. The write endurance of the physical memory is discussed in the article on flash memory; newer technology to increase the storage capacity of a card provides worse write endurance. When reformatting an SD card with a capacity of at least 32 MB (65,536 logical sectors or more), but not more than 2 GB,

FAT16B File Allocation Table (FAT) is a file system developed for personal computers. Originally developed in 1977 for use on floppy disks, it was adapted for use on hard disks and other devices. It is often supported for compatibility reasons by ...

with partition type 06h and

EBPB 4.1 In computing, the BIOS parameter block, often shortened to BPB, is a data structure in the volume boot record (VBR) describing the physical layout of a data storage volume. On partitioned devices, such as hard disks, the BPB describes the volum ...

is recommended if the card is for a consumer device. (FAT16B is also an option for 4 GB cards, but it requires the use of 64 KB clusters, which are not widely supported.) FAT16B does not support cards above 4 GB at all. The SDXC specification mandates the use of

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washin ...

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