Memory cards provide electronic storage space for your digital media such as photos and videos. If you own a digital camera, camcorder, drone, or mobile device, you are likely using a memory card. The best way to find out which memory card you need is in the operating instructions or on the manufacturer's website. However, we have also created the following guide to explain the differences between SD memory cards.
Memory card types
The 3 main types of memory cards are SD Mini, SD Micro, and SD. Each type also has classes that indicate its storage capacity. The most popular classes are SDHC and SDXC.
SD or SDSC (Secure Digital Standard Capacity): maximum storage capacity of 2 GB
SDHC (Secure Digital High Capacity): More than 2 GB to 32 GB storage capacity
SDXC (Secure Digital Extended Capacity): More than 32 GB to 2 TB of storage capacity
The average user can capture hundreds or even thousands of photos and video clips with a 32GB or 64GB card. Hardware devices that support newer standards are backward compatible with older standard cards, but newer SD standard cards cannot be used in hardware devices that only support older standards.
Speed of memory cards
Memory card speed is measured as the maximum number of bytes per second that can be transferred between the SD card and the host device (smartphone, digital camera, drone, etc.). This is especially important if the cards are used in camcorders or for video recording, as the speed of the card will limit the video resolution.
The reading speed is an indicator of how fast you can open a file from the memory card. So when you get a photo from your camera or try to transfer movie data from your memory card to your phone. Write speed measures the card's ability to store data on the memory card.
The most common way of indicating the speed of memory cards used to be a simple class number that looks like a number in a circle. Cards can be classified as Class 2 (minimum write speed of 2 MB / s), Class 4 (4 MB / s), Class 6 (6 MB / s) or Class 10 (10 MB / s). It is important to know that these are minimum values. So it is entirely possible that a card can achieve higher speeds, but these values give you an idea of what to expect at the very least.
More recently, writing speed has been classified using a UHS speed rating that appears as a 1 or 3 in a “U”. UHS-1 cards achieve a minimum of 10 MB / s, while UHS-3 cards promise 30 MB / s.
Some SDHC and SDXC cards also support Ultra High Speed Classification (UHS), which offers higher data transfer rates. A Roman number is often seen on the cards, which indicates the speed of the card interface in relation to the ultra-high-speed classification. UHS-I cards reach up to 104 MB / s, and UHS-II increases the speed up to 312 MB / s.
Test memory cards
Storage Capacity - It is important to remember that a memory card will never have its full storage capacity. The manufacturer has to integrate the file system into the memory card, which takes up a certain amount of storage space. The storage capacity varies from card to card and from manufacturer to manufacturer. For example, with a 124 GB card, you should expect at least 119 GB of available storage space.
When testing the speed of a memory card, it is important to use a card reader with a USB 3.0 port and ensure that the host device (e.g. laptop, smartphone) supports USB 3.0. USB 3.0 enables faster transfer rates between the memory card and the host device (in some cases up to 10 times faster). If you are using a card reader with a USB 2.0 port or a device that only supports USB 2.0, you will not be able to measure the speed of the memory card accurately.
The easiest way to test the storage capacity of a memory card (under Windows) is to right-click on drive D: (or the location where the memory card is located) and select "Properties". On the General tab you should be able to see the used and available space on your memory card. On the “Extras” tab you can check the memory card for any system errors.
The second step is to test the speed of the memory card. To do this, you need to download software from a third party. Some of the most common memory card speed testers are ABC, XZY, and FDE. The software provides the reading and writing speed of the card. At ENJOOY we randomly test our memory cards with ABC software and a USB 3.0 card reader to ensure the speed of the memory cards and the quality of the memory.