Differences between SD Card and SDHC
SD vs. SDHC Cards[edit]
Secure Digital (SD) cards and Secure Digital High Capacity (SDHC) cards are types of flash memory cards used in a wide variety of portable electronic devices.[1] While they share the same physical dimensions, they have notable differences in their capabilities and compatibility with host devices.[2][3] The SDHC standard was introduced in 2006 to address the growing need for storage capacities greater than the original SD card standard could provide.[4][3]
The primary distinction between the two formats lies in their storage capacity and the file system they employ. Standard SD cards have a storage capacity of up to 2GB and typically use the FAT16 file system.[5] In contrast, SDHC cards offer capacities ranging from over 2GB up to 32GB and utilize the FAT32 file system. This difference in file systems is a key factor in their compatibility; the FAT32 system allows for the larger storage volumes found on SDHC cards.
Device compatibility is another critical point of difference. Host devices that support SDHC cards are backward compatible, meaning they can also read and write to standard SD cards. However, the reverse is not true. Older devices manufactured before 2008 that only support the original SD standard are not compatible with SDHC cards. To ensure proper functionality, users should look for the SDHC logo on both the memory card and the host device.
Speed classes also differentiate these cards. The SD Association established speed classes to indicate the minimum sustained write speed, which is particularly important for video recording to prevent frame loss. While both SD and SDHC cards can have various speed class ratings (such as Class 2, 4, 6, and 10), the introduction of the SDHC standard coincided with a greater need for faster write speeds to handle high-definition video.
Comparison Table[edit]
| Category | SD Card | SDHC Card |
|---|---|---|
| Storage Capacity | Up to 2GB | Over 2GB to 32GB |
| File System | FAT16[5] | FAT32 |
| Device Compatibility | Works in SD, SDHC, and SDXC host devices | Works in SDHC and SDXC host devices only |
| Introduction Year | 1999[3] | 2006[4][3] |
| Governing Standard | SD Specification 1.0/1.1 | SD Specification 2.0 |
| Single File Size Limit | 2GB | 4GB |
References[edit]
- ↑ "bhphotovideo.com". Retrieved November 22, 2025.
- ↑ "wikipedia.org". Retrieved November 22, 2025.
- ↑ 3.0 3.1 3.2 3.3 "hugdiy.com". Retrieved November 22, 2025.
- ↑ 4.0 4.1 "lexar.com". Retrieved November 22, 2025.
- ↑ 5.0 5.1 "ssl-images-amazon.com". Retrieved November 22, 2025.
