Have you ever bought a new digital camera but don’t know how to choose a suitable memory card? There is no reason that you spent tens of thousands on a camera but buy it a cheap memory card with poor quality. Memory card used for additional storage for devices, store digital information such as photos and videos. It is commonly used in mobile phones, digital cameras, SLR cameras, etc. Each devices suit different memory cards; the compatibility can usually be found in product manual or official website. The abundance of available memory card products on the market can make selecting very hard. Types of memory card and its’ standard storage capacity are very confusing as well. This buying guide will break down one by one, so that we all can become a little expert and buy memory cards with no doubts in the future.

Types of Memory Card

1. SD memory card

This is the basic format for the SD card. There are 3 standards for the dimensions: Standard, Mini, Micro. A standard SD cards has dimensions of 32x24x2.1 mm. It has a maximum capacity of 2GB, which is far smaller than other format types of SD cards, such as SDHC and SDXC. Typically, the number of original format SD card have greatly dropped in recent years.

2. SDHC memory card

Compared with SD cards, SDHC (Secure Digital High Capacity) supports a faster transfer speed and higher resolution images and videos. SDHC cards have the same size and shape as SD cards. SD cards with capacity over 4GB are classified as SDHC cards. SDHC cards’ capacity is between 4GB to 32GB. It supports ultra high speed class, up to Class 10 and UHS-I speed standards.

3. SDXC memory card

SDXC (Secure Digital eXtended Capacity) are higher capacity version of SDHC memory card. SDXC cards usually have the largest memory capacity among SD card family, ranging between 64GBs and 2TBs. SDXC also are classed in ultra-high speed class format, typically up to UHS-1 speed rating.

4. MicroSD memory card

MicroSD card is a mini version of an SD with a standard size of 15x11x1 mm. Their maximum capacity is 32 GB and maximum transfer speed is 10MB per second. Typically used for small devices such as smartphones, GoPros.

5. Micro SDHC card

The Micro SDHC card is a mini version of the standard SDHC card, which has the same physical size as the MicroSD card and the same memory capacity as SDHC card. It can be inserted in adapter to use in standard SDHC card devices.

6. Micro SDXC memory card

A mini version of SDXC card. Micro SDXC cards are smaller in size and have the same storage capacity as SDXC cards, ranging between 32GB and 2TB.

7. CompactFlash card

CompactFlash Card, or CF card has the largest physical size of all, commonly used in DSLR cameras and digital cameras by professional photographer and videographers. Its memory capacity ranges from 2GB to 512GB. CFast Card is a faster version of CompactFlash, they use SATA 3.0 which can process at speed up to 600MB/s. CFexpress is also a type of CompactFlash card, with a write speed of up to 1480MB/s, one of the fastest memory cards.

Speed Class Ratings

Speed class is an indicator of memory card read speed and write speed. Write speed indicates is how fast data can be saved to the card, expressed in megabytes per second (MBps). There are currently three rating classes: Speed Class, Ultra High Speed (UHS) Speed Class, and Video Speed Class. The SD Association has divided SD cards into the following five classes.

After the introduction of SDHC and SDXC cards, the SD Card Association established a new speed rating system in 2009, known as UHS.

The SD Association established a video speed rating system in 2016.

Tips on Choosing Memory Card

1. Mobile phone

Most mobile phones on the market support 128GB to 256GB memory cards, purchasing 64GB to 128GB is the safest choice. If your main priority is storage, there are also 512GB or 1TB memory card options but check your phone's compatibility before buying it. Fast transfer speed is also critical for memory cards, especially when transferring apps, photos and files to SD card. It was strongly suggested to choose application performance class A2. If you use your smartphone to record 4k videos very often, it was suggested to choose a UHS 3 speed class.

2. Digital camera

A 32GB memory card can hold up to 1,000 RAW photographs. If those photos are in a jpeg format, the number increases to about 3,200. For digital camera, it is most important to choose a memory card with high memory capacity and high speeds, which allows high resolutions images and videos storing.

3. Tablet

Although memory card is used to extend the storage capacity of your tablet but do not be greedy when picking the card. Remember to check your tablet specifications for details before buying, many tablet can only handle memory cards up to 64GB.

4. DSLR camera

SDHC, SDXC cards and CompactFlash (CF) usually are compatible with DSLR cameras, CF cards may be old-school, but it has high transfer speeds and large capacities, it was often used in higher-end DSLRs. MicroSD card is not recommended to use with DSLR camera, it requires SD card adaptor and there is a possibility of failure between transfers. 64GB or 128GB is sufficient storage for everyday use, a 64GB card can hold around 2132 pictures. If you are using for vacation, 128/256 GB is more suitable. A U3 rating speed can transfer HD photography and 4K Ultra HD videography smoothly.

5. Switch

Switch supports Micro SD, Micro SDHC, and Micro SDXC. They only support the speed class of UHS-I, UHS-II is not applicable. The internal storage can only hold four to five games, so it is recommended to buy a MicroSD card of 256GB or more. If you use a U3 memory card, the speed of reading the game is already very fast. Due to the speed level limitation , there is no need to buy the best configuration for the memory card, recommend you to choose a MicroSD card with a good value.

6. Action camera

Memory card with a capacity of 32GB to 128GB is generally recommended. 32GB supports up to 5 hours of recording time if recorded in Full HD. The ideal speed class would be write speed greater than 80MB/s, which allows you to transfer and copy saved files at a much faster speed. Since action camera sometimes need to be used in harsh environments, it is important to choose memory card that is waterproof and shockproof.

7. Dash camera

Dash camera usually use MicroSD cards. The most important thing to look at when choosing dash cam is its’ recording time, the ideal recording time should be around 40,000 hours. For most people, 32GB should be enough for a commute. 64GB if your dash cam has a parking mode. When choosing a dash camera, make sure to look at the durability of the SD card, whether it is shockproof and high temperature resistant. If your dash cam can record in 4K, remember to choose cards with write speeds of Class 10 or higher.

8. Security Camera IP CAM

Most IP camera are compatible with MicroSD-size memory cards. If your home security camera is in non-stop recording mode, it was suggested to buy a space memory card with a large storage space, a 128GB MicroSD card can usually record for at least one week. If it records only after motion detection, 64GB should be a great choice. In terms of write speed, C10 or U1 is recommended.