Which type micro sd card do I look for?
Hi, Using a U1 card is a risk. It may be ok for photos but for video you should use V30 or U3. See long story below:
‘Speed Class’ refers to the absolute minimum sustained write speeds. Cards can be rated as Class 2 (minimum write speed of 2MB/s), Class 4 (4MB/s), Class 6 (6MB/s) or Class 10 (10MB/s). The next rating is the UHS Speed Class. This stands for Ultra High Speed and refers to minimum sustained writing performance for recording video. UHS came about due to 4K-capable video devices needing faster write speeds. There are two UHS Speed Classes, UHS Speed Class 1 and UHS Speed Class 3. UHS Speed Class 1 supports a minimum 10MB/s write speed, whereas UHS Speed Class 3 supports at least 30MB/s write speed. The UHS Speed Class is denoted by either a 1 or 3 inside of a bucket U symbol. As a rule of thumb, 4K-capable camcorders will usually require at least a U3 rated SD card. Extremely high-resolution video (4 or 8K), demanded even faster cards and this is provided by V class which range from 6 to 90. The number represents MB/sec. Confused yet? Keep reading. So, going from fastest to slowest with these numbers it is V90, V60, V30 (which is equal to U3) V10 (which is equal to U1 and Speed Class 10). The remaining are not worth considering.
Also, for drones ignore
A1 and
A2 ratings and just pay attention to V ratings. The A ratings are for application extensive operations such as smartphones and mobile gaming consoles. This is the Application Performance Class Specification. These cards essentially extend the memory of these devices. The apps that run on these devices interact with memory space differently. Rather than a stream of sequential data (think video), they write a lot of small chunks of data wherever there's space available. That's known as random read/write (compared to sequential read/write that's important for video). A card that is suitable for random reading and writing may not be suitable for sequential reading and writing. The
A1 and
A2 cards have different random read and write ratings but have the same minimum sequential write speed of 10 megabytes per second. This speed is equivalent to the Class 10 video speed rating. The Class 10 rating is about the same is the V10 rating. The V10 rating is too slow for your drone.
So, the bottom line for your drone camera (at least DJI drones) you need a minimum V30 card (or U3). The card may also have other ratings (Such as A or U) but if it says V30 or better you are good. And as always, the best bet is to see what the manufacturer recommends/requires. But keeping it simple = V30 minimum.
DJI recommends the following :
SanDisk Extreme PRO 64GB V30
A2 microSDXC
SanDisk High Endurance 64GB V30 microSDXC
SanDisk Extreme 64GB V30
A2 microSDXC
SanDisk Extreme 128GB V30
A2 microSDXC
SanDisk Extreme 256GB V30
A2 microSDXC
Lexar 667x 64GB V30
A2 microSDXC
Lexar High-Endurance 64GB V30 microSDXC
Samsung EVO Plus (Yellow) 64GB microSDXC
Samsung EVO Plus (Red) 64GB microSDXC
Samsung EVO Plus 128GB microSDXC
Samsung EVO Plus 256GB microSDXC
Kingston V30 128GB microSDXC
Netac 256GB
A1 microSDXC