CARDS - WHAT IS THE DIFFERENCE BETWEEN SDHC AND SD CARDS?
What is the Meaning of Class in Memory Cards ??
What is the Meaning of Class in Memory Cards ??
A SD card will normally work in a SDHC device (possibly with lower performance). SD cards are in the following capacities 4,8,16,32,64,128,256 512MB and 1GB, 2GB only. Currently mainly 2GB SD cards are being sold.
A SDHC card will not work in a SD device such as a camera or reader. SDHC cards are in the following capacities 4GB, 8GB, 16GB and 32GB
SDHC (Secure Digital High Capacity) was established to meet the growing demand for HD (High Definition) video and high resolution image recording now used in many SD-enabled devices.
SDHC is the same physical size and shape as standard SD but meets the new SD specification of version 2.0. If the SD card is 4GB or above, it is classed as a SDHC card. Currently, SDHC specifications allow for memory cards of a capacity between 4GB and 32GB.
SDA (SD Card Association) has also established a Speed Class rating (Class 2, 4, 6 and 10) for thestandardisation of data transfer speeds (compulsory for SDHC cards):
- CLASS 2 - a guaranteed minimum write speed of 2MB/s or higher*
- CLASS 4 - a guaranteed minimum write speed of 4MB/s or higher*
- CLASS 6 - a guaranteed minimum write speed of 6MB/s or higher*
- CLASS 10 - a guaranteed minimum write speed of 10MB/s or higher*
- * The minimum speed capability depends on the manufacturer of the host device and model.
All Class 2, Class 4, Class 6 and Class 10 SDHC cards are compatible with SDHC devices. Please note that if the device manual suggests a SDHC card of speed Class 4 as a minimum, the user should install a Class 4, Class 6 or Class 10 (faster) SDHC, NOT a Class 2 card as this may reduce performance of the device.
SDHC cards are not backwards compatible with standard SD devices, so they may not work in digital cameras or USB Memory Card Readers manufactured before summer 2007.
Most new devices that require the new SDHC format to operate will display the SDHC logo on the product (such as printed on the side of a camera casing) and/or user guide.
Standard SD Cards will work in SDHC compatible devices such as Memory Card Readers. In a SDHC camera a standard SD may be of limited use due to the slower read and write speed of this older technology.
The information contained in this FAQ also applies to microSD and new microSDHC plus miniSD and new miniSDHC formats. The only difference will be the physical size of the memory cards, the speed class information and compatibility issues are the same.
The Secure Digital memory card standard ensures interoperability among devices. It's supported by most small electronic devices that use memory cards for storage. A regular SD card uses the first version of the standard, which limits its maximum storage capacity. SDHC cards, which use a later version of the standard, can store more data and may also support ultra high-speed data transfer rates that a regular SD card does not support. SD standards are only backward compatible, which means that an SDHC card may not work in every device or card reader that supports the SD standard.SD Cards
SD and SDHC cards are memory cards you can use to store files, music, pictures, video and any other data. Panasonic, SanDisk and Toshiba initially created the SD standard, which defines memory card specifications such as size, capacity, speed, security and power. SD and SDHC cards are typically used with small electronic devices such as cameras, cell phones and tablets, and can be read by laptop and desktop computers with a compatible card reader.Capacity and Format
The primary differences between an SD card and an SDHC card are maximum storage capacities and default file format. A standard SD card is manufactured in versions that store up to 2GB of data using FAT16 as the default format. An SDHC card is manufactured in versions that store from 4GB up to 32GB of data using FAT32 as the default format. Both types of cards come in three different physical sizes: full SD, mini SD and micro SD.Compatibility
SD standards are backward but not forward compatible. This means that a device that supports only the SD standard cannot read or write to an SDHC card, but a device designed for SDHC cards can read and write to an SD card. The SD extended capacity, or SDXC, standard supersedes SDHC. SDHC devices can't read or write to SDXC cards, but SDXC card readers can read and write to both SD and SDHC cards.Speed
The SD card you use with a video recorder has to save data at least as fast as the recorder streams it. Higher video resolutions stream more data per second. SD cards have a speed class rating that defines how fast the card saves data. SD and SDHC cards may have a speed class rating of 2, 4, 6 or 10, where 2 is slowest and 10 is fastest. Speed class 1, also called Ultra-High Speed is the fastest. UHS did not exist when the SD standard was created and is only available with SDHC and SDXC cards.
