Best Memory Cards Canon EOS R | Tested In-Camera

We tested all the most popular UHS-I and UHS-II memory cards in the Canon EOS R to see which cards performed the best in-camera.

Use this guide to find the fastest sd cards for the EOS R.

Canon EOS R – Amazon / Adorama / BHphoto

Best Memory Cards Canon EOS R

The Canon EOS R is no slouch when it comes to data output. With 8fps continuous burst shooting speeds the Canon R can produce a RAW image data stream of more than 250Mbps and it doesn’t stop there. Video specs are very data-heavy with 4k video having an output of 480Mbps and 1080p video has 180Mbps.

To get the full benefit of the amazing data output, it may be a good idea to buy the fastest memory card.

The Canon EOS R has a single card slot that supports UHS-II memory cards of any capacity.

Top 5 Recommended Memory Cards For The Canon EOS R

Here is a quick list of the top five best memory cards you can buy for the Canon EOS R with the included in-camera write speeds.

You can use slower v60 cards if you’re shooting a lot of video, but be careful not to use cards too slow otherwise they will not support Canon’s 400Mbps video bitrate. You need cards with at least a 55-60MB/s performance to use the high-quality 480Mbps 4k video that the EOS R outputs.

Must-Have Accessories Canon R

Canon EOS R Speed Test

I’ve tested all the most popular SD memory cards for the Canon EOS R to find out which ones work the best for serious shooters and more casual shooters. I’ve also tested each card shooting at 480mpbs 4k video. 

Canon EOS R Speed Chart

USB 3.0 speeds were acquired using Crystal Disk on Windows 10. A few cards I still need to update.

Read more about 4k compatibility below.

Canon EOS R Specs

List of Canon RF Lenses

Testing SD Memory Cards Canon EOS R

The Method

There are a few different ways to test the cards that I’ve worked out, but I’ve found the most reliable still is to record a burst sequence and calculate the time the buffer takes to clear. There is another method that involves counting the shots and data and comparing it to the size of the buffer. While that method is very fast in terms of man-hours of churning through data, I’ve found it not as accurate as it doesn’t account for hiccups and it’s very difficult to determine the usable size of the buffer. On the Canon R, the usable buffer is somewhere around 835 MB.

The 4K Video Test

I do 4k video tests in all my camera tests now. The Canon EOS R will output 4k video at 480mbps which equals 60MB/s. So you will absolutely want to buy an SD card that is a v60 UHS-II card if you want reliable 4k performance. However, I’ve found that a lot of U3 UHS-I cards still work fine, but I wouldn’t recommend them for serious shooters.

I do my 4k tests by shooting a TV to make sure I maximize the bitrate, because it will vary depending on what you shoot. I record for usually at least 2 minutes. If at any point I get a buffer indicator I mark the card as incompatible

Again for 4k video on the EOS R, I recommend at least a v60 card, but even those sometimes have issues so go with v90 if you can. Some cards like the fast 300MB/s Sandisk and Sony cards don’t have the V rate, so just buy the 300MB or Sony G cards.

Best SD Memory Cards For 4k Video With The Canon R

You really only need to be picky with your memory cards when shooting 4k video with the Canon EOS R. 

This camera is capable of outputting 480mbps when shooting 4k video which translates to 60MB/s.

With 1080p you can get a bitrate of 180mbps which translates to 22.5 MB/s. 

While UHS-I memory cards are capable of producing speeds of 60MB/s or faster, they usually max with a speed class of U3.

The U3 rating only guarantees a minimum datarate of 30MB/s. So even though you get a Sandisk Extreme Pro that can write at 62MB/s, it may cause issues with very long recordings, or it could degrade over the years and drop in speed.

However . . .

You might be looking at my chart and seeing that some cards were producing slower speeds that 60MB/s but they were still working fine for 4k video. This is because recording a stream of photos takes more processing power and slows down the system more so than video. The processing of shooting photos has several steps in it, and the multi-threading capabilities of the EOS R is limited with the Digic 8 processor. The Digic 8 is also not said to be dual or even quad-core like we see in some other cameras. Even still, other brands probably keep all their memory card processing reserved for one core, so the other cores can calculate for AWB, focusing and exposure.

This single-core processor is likely why we see limitations with silent shooting and eye AF when in Servo or burst modes.

With a single thread, when each photo gets created, the raw data is sent to the buffer, then processed before it is sent to the memory card. Each shot is written to the memory card from the buffer produces a very small delay as it is processed, slowing down the memory card write speeds seen in my test. It slows down even more if you shoot RAW+JPG usually by up to 20MB/s because even more processing has to happen to each image before they are written to the card.

When it comes to writing video, there is no multi-step processing and the data stream can record to the card much faster, but there is no way for me to test this. I would assume that you would see probably a +10MB/s speed increase when just recording video. This is why many of the cards that are listed above with speeds of 50MB/s are still working for me when doing 4k tests, because they are actually recording slightly faster when streaming video from the buffer to the card.

Shooting 1080p

If you plan on only shooting 1080p and you’re not doing a lot of burst photography, a good UHS-I memory card is all you’ll need. 

1080p produces a data rate of 180mbps which translates to 22.5MB/s and most memory cards, even the slow Evo and Ultra cards can produce those speeds.

However, when shooting video, it will still be important to buy a trustworthy and reliable brand.

What The Numbers And Letters Mean On Each Card

On each and every memory card is written a bunch of numbers and letters. These letters are always changing as ratings and speed classes are constantly changing. As technology becomes more demanding, new codes need to be listed. For example with micro SD memory cards, you may see A1 and A2. These cards are designed for running mobile applications and games that read and write to memory cards randomly compared to sequentially.

Memory cards for cameras only write sequentially so there are fewer requirements for these SD memory cards.

Here are the codes you need to know when buying SD memory cards for the Canon R.

U1, U3, v30, v60, v90 

These numbers represent the speed class and has to do with the minimum speed of each card.

U1, U3 is 10MBs and 30MB/s respectively.

v30, v60, v90 is 30MB/s, 60MB/s and 90MB/s represents minimum write speeds.

You may also see older cards say Class 10. These have a minimum of 10MB/s like U1 cards.

UHS-I vs. UHS-II

UHS-I and UHS-II is another performance class but UHS-II requires a compatible camera. The Canon R is UHS-II compatible.

There is a physical difference between UHS-I and UHS-II memory cards. UHS-II cards have a second set of pins. The camera must also have a second set of pins inside the SD card slot to read and write UHS-II cards. UHS-II cards can work in UHS-I cameras, but they will be limited to UHS-I speeds. UHS-I cards can also work in UHS-II cameras but will also be limited to UHS-I speeds.

SDXC / SDHC

SDXC and SDHC have to do with the file system the card is capable of handling.

SDHC cards will always be 32GB or smaller and will only be able to record data that is 32 bit. In other words, if you use a 32GB card that is SDHC, you will be limited to a fat32 file system and a 4GB file size limit. If you try to record video to a 32bit card, the files are broken into 4GB chunks.

SDXC uses an exFat filesystem that is 64-bit. If you record video to a 64-bit card, you will be able to record video clips larger than 4GB as a single clip.

Canon EOS Tips

Can You Use Micro SD Memory Cards In The EOS R?

I get this question a lot, so I spent some time testing various micro SD memory cards in various cameras.

I’ve found that many micro SD memory cards are capable of matching the speeds of the bigger brother, however, a lot of micro SD memory cards still run slower so it depends on the brand and the model.

The problem with micro SD memory cards is you have to use an adapter and this is the weak link.

While I’ve found the micro SD memory cards can perform very well, I’ve found the adapters often cause issues. Cards can vibrate and lose connection with the adapter, or some of the adapters are just bad.

Because of this, I do not recommend you use micro SD cards unless it’s an emergency. If you’re shooting regularly, you should buy an SD memory card for your Canon R, so you don’t run into memory card problems.

This doesn’t mean you should never use Micro SD cards. I shoot with GoPros, Drones and various cameras so I like to keep a backup micro SD card in my bag because it will work in any device just in case I ever kill a card or forget one.

Formatting Your Cards

You should always format your memory cards in the Canon EOS R for the best performance. Formatting your cards in other devices before using them in the Canon can cause issues. I’ve had so many issues with the DJI Mavic Pro 2 because of this. You must format the cards in the Camera.

If for whatever reason the camera does not recognize the card, try formatting it again in different systems until you can get it to work. For example, cards that didn’t work in my Mavic 2 Pro, I had to format in a GoPro Hero 7 first. When they were formatted in an Android phone they would not work.

I’ve never seen this issue in Canon, but it’s still a good idea to always format in camera.

Best Memory Card Canon R | Bottom Line

There are a couple of other websites doing these speed tests now, but this site and cameramemoryspeed were the first. I actually started a few months before them, so this site is the original memory card speed test site. Kinda cool hu?

I try to keep it more casual with an open discussion. I’ve learned about a lot of issues from user feedback which allows me to always refine which cards are recommended. Luckily Canon is the most capable brand when it comes to memory cards out of all the cameras I tested. Canon is the best when it comes to memory card compatibility.

When it comes to buying memory cards for the EOS R, it will depend on how you shoot. If you plan on shooting 4k and do a lot of burst photography, I highly recommend you get one of the nice UHS-II cards I’ve recommended.

If you only plan to shoot 1080p and shoot landscape photography or any other slower type of style, then UHS-I cards will be a lot friendlier to your wallet and they will be fully capable of handling those tasks.