What's the difference between SDHC memory card and SDXC memory card?

There are three main differences between SDHC memory card and SDXC memory card, as follows:

The maximum capacity of 1 and SDXC is much higher than that of SDHC. The maximum capacity of SDHC is 32GB, and the maximum capacity of SDXC is 2TB.

2. The data transmission speed is different. The transmission speed of SDXC is 300MB/s, while the highest data transmission speed of SDHC is 65438+1100mb/s. ..

3. The compatibility of directories is different. SDHC memory card is one of the most popular memory cards in the market at present. It is compatible with most devices and backward compatible. However, SDXC has just been launched, and it can only be compatible with very few devices due to market demand.

Extended data:

SDHC memory card

1, the main feature of SDHC is that the file format has been upgraded from the previous FAT 12 and FAT 16 to FAT32, with a maximum support of 32GB. At the same time, the transmission speed is redefined as Class2, Class4 and Class6, and the high-speed SD card can support real-time storage of high-resolution video recording.

2. Compatibility. SDHC still follows the backward compatibility principle of SD card. Because SDHC adopts a different addressing method from SD 1. 1 specification, and it is not compatible with the old version of SD equipment produced before the establishment of SD2.0 specification, only SD equipment that meets SD 2.0 specification and higher can use SDHC.

3. Speed level. Due to the characteristics of flash memory, the actual transmission speed of each memory module will be slightly different. If the speed changes, it will be difficult to record streaming content such as video reliably, because the writing speed must be consistent when recording streaming content.

Speed class and UHS speed class can provide consistent speed for video recording by specifying the minimum writing performance, so as to ensure that cameras, video recorders and other devices with video recording capabilities can still maintain the lowest and consistent speed when performing conditional writing operations specified in the specification.

Speed grade

Due to the characteristics of flash memory, the actual transmission speed of each memory module will be slightly different. If the speed changes, it will be difficult to record streaming content such as video reliably, because the writing speed must be consistent when recording streaming content. Speed class and UHS speed class can provide consistent speed for video recording by specifying the minimum writing performance, so as to ensure that cameras, video recorders and other devices with video recording capabilities can still maintain the lowest and consistent speed when performing conditional writing operations specified in the specification.

SDXC

1, function, although SDXC memory card is based on NAND flash technology like mainstream SD card, its capacity is much higher than that of previous SDHC. The ordinary capacity of SDXC standard can reach 64GB, and the theoretical capacity is 2TB, which is 64 times the maximum capacity of existing SDHC memory cards.

Figuratively speaking, 2TB space can accommodate about 100 HD movies, or 60 hours of HD video, or more than 4,000 RAW photos, or17,000 high-quality photos. The capacity of SDXC standard has reached such an amazing level, mainly due to its adoption of Microsoft exFAT file format.

2. Technical indicators

At present, the maximum capacity of (1) SDXC memory card can reach 5 12GB, and the theoretical maximum capacity can reach 2TB.

(2) UHS 104 provides the traditional SD interface -3.3V DS (25mhz)/HS (50mhz), and the new SDHC memory card supporting UHS 104 is compatible with the existing SDHC counterpart equipment.

(3) SDXC memory cards are only compatible with SDXC devices with exFAT file system. It cannot be used for SD or SDHC counterparts.

(4) Adopt the most reliable CPRM copyright protection technology.

(5)UHS-I is a new ultra-high speed interface specification, and the data bus transmission rate is 104MB per second. This is the highest standard in SD new memory card standard Ver.4.00

main products

Sandisk's 128GB SDXC UHS-I memory card is based on UHS-I technology, which aims to enable users to shoot high-quality videos for hours on end. The reading and writing speed of SanDisk Extreme SDXC card is 45M per second, which enables photographers to continuously take high-resolution photos and then quickly transfer files to the computer. Its speed is reflected in that the photographer can download an hour of full HD video content in 5 minutes, or transmit 500 HD photos in 1 minute.

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Baidu encyclopedia -SDXC memory card

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