About memory cards

A memory card is a secure digital storage card empowered by semiconductor flash memory.

Your phone uses a micro memory card with a dimension of 15 mm x 11 mm x 1 mm (0.59 in. x 0.43 in. x 0.04 in.), which is smaller than the standard memory card. The following figure shows a standard memory card and two micro memory cards.

SDHC refers to Secure Digital High Capacity. SDHC cards feature a relatively larger capacity.

SDXC refers to Secure Digital Extended Capacity. SDXC cards feature an even larger capacity compared to SDHC cards.

SD card capacity: ≤ 2 GB

SDHC card capacity: 4–32 GB

SDXC card capacity: > 64 GB

The flash memory speed is rated by speed classes, while various speed classes indicate different read and write speeds.

In a class mark, the number after "Class" indicates the read speed per second. For example, Class 2 offers a read speed of 2 MB/s.

The capabilities of each speed class are as follows:

Class 2: 2 MB/s. Fast enough to watch a standard MPEG-2 or MPEG-4 movie, play back standard-definition TV (SDTV) videos, or take photos on a digital camera.

Class 4: 4 MB/s. Fast enough to play back high-definition TV (HDTV) videos smoothly and take burst photos on a digital camera.

Class 6: 6 MB/s. Fast enough to take burst photos on an SLR camera or other professional photography devices.

Class 10: 10 MB/S. Fast enough for operations that require even higher storage speed.

Check the label on your memory card, as shown in the following figure. The number "10" in the red box indicates that the memory card's speed class is 10.

Mainstream memory card manufacturers include SanDisk, Kingston, Toshiba, Samsung, and Sony.

1. The memory card may have a low speed class.
   • There may be a quality issue with the memory card.
   • The size of the memory card may not be fully compatible with your phone, resulting in a poor contact between the card and your phone.
   • The memory card may have been formatted to NTFS. Please keep it in FAT format.
2. A large number of small files may be transferring.The pauses between individual file transfers may make it seem like the memory card's read and write speeds are slow.
3. The memory may be insufficient due to an excessive number of apps running simultaneously.
4. There may be an issue with your phone.