Memory Cards for Phones

Type and Capacity of Memory Cards for Phones

MicroSD memory card for a phone is a reduced format derived from SD cards for phones. Due to the need for more capacity, newer generations of microSDHC (Secure Digital High Capacity) and microSDXC (Secure Digital eXtended Capacity) were created. The physical dimensions of these versions are the same as microSD.

• MicroSD cards - capacity of 8MB to 2GB. People shun them these days because of insufficient capacity.
• MicroSDHC cards - capacity of 4 to 32GB. This is a commonly used standard.
• MicroSDXC cards - capacity of 64GB to 2TB (potential maximum. So far, we have 512GB at most).

Beware of Backward Compatibility Between Generations of Memory Cards for Phones

Not all memory cards for phones are interchangeable. Devices that are made with only microSDHC card support will not "see" (read) a microSDXC card. So, before buying a memory card for a phone, whether it is a micro SDXC card or another version, make sure you know what type of card your device supports and what maximum capacity it can handle. Of course, devices that support microSDXC cards also support the older microSDHC and microSD cards.

Read and Write Speeds of Memory Cards for Phones

Memory cards for phones are divided according to speed class (referred to as "class"). The class number indicates the minimum guaranteed write speed of the phone memory card. In practice, the read speed is always equal to or faster than the write speed.

Class	Logo	Min write speed	Suitable for
Class 4		4MB/s	HD video recording
Class 6		6MB/s	HD video recording
Class 10		10MB/s	Full HD video recording
UHS-1		10MB/s	Real-time video streaming.  Recording of long HD videos
UHS-3		30MB/s	4K video recording

The speed of the SD card affects not only how well it can record video, but also how quickly you can save photos and open apps. We recommend using at least a Class 10 memory phone card that can record Full HD video and whose effect on the phone's response will be almost imperceptible.

Memory