Many FPV devices require an SD card to work. In this guide I will recommend what micro SD cards to buy for GoPro cameras, Fatshark DVR, Taranis radio, as well as DJI drones. I will also explain the speed class letters on SD card labels.
Check out our buyer’s guide on HD cameras for FPV drones.
Table of Content
- What SD Cards Should I Buy?
- Physical Sizes
- Memory Capacity
- What Are All the Numbers and Letters?
- Calculate Speed and Capacity Requirement
- Tips for FPV Pilots
GoPro Hero, Session or Other HD Cameras
The following SD cards are popular for the GoPro and other HD cameras. 32GB and 64GB are good sizes, 128GB or bigger might or might not be supported, check GoPro’s compatibility chart to confirm. (For other cameras, check manual).
These cards are great for 1080p, 2.7K as well as 4K!
- Samsung Evo Select (Get the 64GB): https://amzn.to/2tH7YDE
- SanDisk Extreme (32GB and 64GB): https://amzn.to/2XkLqWR
The Samsung Evo is truly the best bang for the buck, unbelievable value! The Sandisk Extreme is awesome in terms of compatibility as it’s the most recommended card by GoPro (in nearly all of their models).
For only 1080p videos, check out Lexar 1000X: https://amzn.to/2VnzJg9
It’s a good idea to get a card that can handle 4K recording, since that is becoming the standard on cameras for FPV. Even if you don’t shoot in 2.7K or 4K, but only 1080p, It still makes sense because it’s future-proof and doesn’t actually cost much more. For 4K recording, look for SD cards with U3 (or V30) speed rating.
As far as capacity goes, it depends on how much footage you plan to record in one go. I will show you how to estimate the amount of footage you can store in an SD later in this article. 32GB and 64GB are the popular options for FPV. The next level up is 128GB but check if your camera supports that.
FPV Goggles and DVR
SanDisk Ultra 16GB: https://amzn.to/2VlNyf9
Most DVR’s use FAT32 for the file system format, including the one inside the FatShark FPV Goggles. In a nutshell, FAT32 supports a maximum capacity of 32GB. Therefore I would advise against using an SD card that is bigger than 32GB in DVR and Fatshark goggles.
A 16GB SD card should really be more than sufficient for a day of flying (for example, on my HDO it gives me just a little over 5 hours of footage). If you’re going for a weekend then use a 32GB card, or just take a few of them.
Flight Controller Blackbox
Samsung Evo (32GB): https://amzn.to/2tH7YDE
Radio (Taranis & Nirvana)
Radios like the Taranis X9D, QX7 and the Flysky Nirvana come with a really basic 2GB micro SD card (what I really mean is cheap and slow). For any reason you want to get a new card for it, this one should do just fine:
An SD card is not required, but it can make your radio more powerful and fun to use. It stores the resource files like voice pack, logos, firmware files and scripts etc.
The speed of the card might affect how fast these resources can be loaded. But generally speaking the requirement is quite low, since these files are relatively small. As far as I know, literally any 2GB to 32GB cards should be fine.
DJI Camera Drones
SanDisk Extreme (64GB and 128GB): https://amzn.to/2HahuHp
SD card requirements for camera drones such as the DJI Mavic and Phantoms, are similar to the GoPro, since it’s essentially just a camera.
DJI camera drones currently support SD cards with maximum capacity up to 64GB or 128GB depending on the model. For example the DJI Spark supports up to 64GB cards while the DJI Mavic Pro supports up to 128GB.
- 32GB Class 10 card for only $8: https://amzn.to/2XpyS0m
- 8GB Class 10 Micro with Adapter for only $5: http://bit.ly/2TeYuhV (not tested)
Most 3D printers are still using standard sized SD card, or you can just use a cheap micro SD card with an adapter.
Cards basic specs should do just fine. It doesn’t have to be huge in capacity either since STL files are generally not very big. 8GB, 16GB or 32GB would be more than enough. I have been using a 2GB card since 2015, not seen the need to upgrade yet.
Now let’s talk about the technical aspects of SD cards.
SD Card Sizes
SD cards come in various physical sizes, the two most popular sizes are “Standard SD Cards” (or normally just “SD cards“), and “Micro SD Cards“. Here are the dimensions:
- SD cards: 32.0 × 24.0 × 2.1 mm
- Micro SD cards: 15.0 × 11.0 × 1.0 mm
“Micro SD cards” are used for most things in FPV, which almost never actually use the bigger “SD cards”.
SD cards and Micro SD cards are basically the same thing, except Micro SD cards are much smaller. Micro SD cards usually come with an adapter for converting to the form factor of a normal SD card. That’s because many SD Card Readers still only support standard SD card form factor.
The capacity of an SD card is normally measured in GB (gigabytes).
Pro Tip: 1024 MB = 1GB, 1024 GB = 1 TB
Note that some older devices and card readers don’t support SD cards larger than 32GB. This is due to the type of file formatting which are either SDHC (microSDHC, HC), or SDXC (microSDXC, XC). These formats are also indication of their potential maximum capacity.
- SDHC goes up to 32GB
- SDXC goes from 32GB up to 2TB
That means if an SD card is 32GB or smaller, it’s probably SDHC, while if a card is 64GB or larger, it’s probably SDXC.
Another limitation of SDHC, is that it uses FAT32 file system. With FAT32, you can’t write files larger than 4GB. Files exceeding 4GB would have to be split up and put in separate files. Therefore SDHC is not ideal for high definition videos, but fine for photos.
What are all the numbers and letters on SD card?
The speed class rating and figures are normally printed on the SD card. But the rating systems can be confusing for new comers. This is partly due to the rapidly growing technology and requirements in our cameras. Older rating classes are quickly reaching their limits and new ratings are introduced to meet the new requirements.
I will touch on each of these speed classes to give you a basic understanding.
Read and Write Speeds
The speed of an SD card is the data transfer rate, this is usually printed on the label or stated in the product page to give you a rough idea of the performance to be expected. There are read speed (R) and write speed (W).
The “MB/s” figure you could find on the label is normally the “maximum achievable read speed”. That’s because it’s usually the biggest number and it looks good for marketing.
Pro Tip: 1 Byte = 8 bits. Byte with a big “B” and bit with a small “b”. When people are talking about 80Mb/s, it’s really just 10MB/s. So don’t get confused!
Depending on the application, write speed can be just as important as read speed, in fact, more important in some cases. For example, for a camera, if the SD card has a slow write speed and fails to keep up, you will find dropped frames and stuttering in the video.
This is the oldest speed class you can find on modern SD cards. The number indicates the minimum sustained write speed:
- Class 2: 2MB/s or above
- Class 4: 4MB/s or above
- Class 6: 6MB/s or above
- Class 10: 10MB/s or above
In my opinion, this is an outdated (useless) speed class, because it’s very rare nowadays to find cards that are slower than Class 10. Even if you can find slower cards, there is no reason to buy them as the price difference is nearly non-existent.
Later on newer and faster speed classes were introduced.
UHS BUS Interface
UHS (ultra high speed) BUS is a new generation interface for faster data transfer rate. UHS interface compatible cards have a roman number I or II showing on the label.
- Non-UHS cards max out at 25MB/s
- UHS-I cards max out at 104MB/s
- UHS-II cards max out at 312MB/s
Notice that UHS-II cards have a second row of pins that allows for even faster maximum achievable speed. But your device or card reader has to be compatible with UHS-II for it to work, otherwise it will be treated as an UHS-I card.
UHS Speed Class
UHS BUS compatible SD cards are rated by their minimum sustained write speed.
- U1: 10MB/s or higher
- U3: 30MB/s or higher
Basically U1 is equivalent to Class 10, but the card is using UHS-I Bus or UHS-II Bus.
Video Speed Class
When you get into the realm of shooting 4K and 8K videos, you will have to know about “Video Speed Class”.
Video Speed Class is designed for cameras to identify which cards are capable of recording ultra high definition videos like 4K or 8K, or intensive data transfer required by 360 and 3D videos. The number in video speed class indicates the minimum sustained write speed.
- V30: 30MB/s or above
- V60: 60MB/s or above
- V90: 90MB/s or above
For 4K videos you should be looking for at least U3, or better, V30. For 8K videos, V60.
Application Performance Class
The Application Performance class is designed more for mobile and gaming consoles that kind of things, where random write and read speeds are more important.
SD cards with this rating offer more consistent performance while running apps off devices. They have a minimum sustained sequential write speed of 10MB/s, and guarantee “random read and write speeds” that are measured in IOPS (Input/Output Operations Per Second).
- A1: minimum random read speed 1500 IOPS, random write speed 500 IOPS
- A2: minimum random read speed 4000 IOPS, random write speed 2000 IOPS
Calculate Capacity and Speed Requirement
You can estimate roughly how much footage your SD card can store, simply by dividing the total capacity by the bitrate of your camera recording.
Finding Out Bitrate
Bitrate changes when you change camera settings (resolution, frame rate etc), so I am making the assumption that you don’t change settings.
You can find out the bitrate by recording a short sample video, move on to your computer, right click on the file and check properties. Total bitrate is what you want.
In our case, it’s 60163kbps we want.
You want to convert it from kbps (kilo bits per second) to Gbps (giga bits per second) first. You can do this easily with the help from Google, just type “60163 kbps to Gbps” in Google. I am getting 0.060163 Gbps.
Pro Tip: 1 Mbps = 1000 kbps, 1000Mbps = 1Gbps
And don’t forget to divide it by 8 in order to convert it from bits to bytes: 0.060163/8 = 0.00752 GB/s. This is how much date the camera is writing to the SD card every second.
Estimating the Length of Footage
A 32GB SD card can store 32/0.00752 = 4255 seconds, which is 70.9 minutes.
Meeting Speed Requirement
Your SD card has to be fast enough to avoid dropped frames and stuttering.
The speed requirement is the bit rate of the video we discovered earlier. Since SD card speed is measured in MB/s, we have to convert bit rate to the same unit first. Simply type bit rate in google “60163 kbps to Mbps”, then divide the answer by 8.
60163kbps = 60.163Mbps, and 60.163/8 = 7.52 MB/s.
This means that in every second our camera records 7.52 MB of footage, and your SD card should have a minimum sustained write speed of 7.52 MB/s.
To meet this requirement, Class 10, or U1 class should do fine.
SD Card Tips for FPV Pilots
Avoid Unknown Vendor
To avoid getting fake SD cards, don’t buy from unknown vendors. If you are getting it from Amazon or eBay, avoid vendors with few reviews.
Leave Contact Info In SD Card
Create a text file in the SD card, name it “read if found.txt”, and put your contact information in there. If your quadcopter have a “fly-away” and someone finds it, at least there is a possibility that they can contact you and return it.
I always format new SD cards inside the camera or DVR I am going to use it with! This ensure the formatting will be compatible.
Getting 64GB Cards or Larger
If you plan to use large capacity cards (64GB or more), make sure your device is SDXC compatible.
All quoted speed numbers are from wikipedia: https://en.wikipedia.org/wiki/SD_card