Best SD Cards Sony A7III – In-Camera Benchmarks

SD Cards for Sony A7III

Here are a few useful tips to help you decide what the best SD Card for Sony A7III is for your shooting style.

The Sony A7III features dual memory card slots, but only one of those slots is UHS-II compatible.  The second slot is only UHS-I.

If you require always shooting a RAW backup, then there is no point in using UHS-II memory cards in either slot, because slot-II, which is UHS-I will slow down performance to that level. That right there should save you a lot of money if you have to shoot RAW backup because you’ll only need to buy UHS-I cards.

You can shoot RAW with JPG as your backup and your UHS-II speeds will still perform quickly, although expect to lose about 20MB/s in buffer clearing speeds when shooting RAW+JPG because of the extra processing time to write the JPG files.

For Video, UHS-I memory cards are all you need as they have a U3 rating. The Sony A7III only shoots 4k video at 100Mbps, which translates to 12MB/s. Most UHS-I cards can perform at these speeds, but the camera will require you to at least use a U3 memory card. It will not allow you to use a U1 card with 4k video because it requires the 30MB/s minimum write speed that U3 cards have.

Best SD Cards for Sony A7III & Recommendations

V90 UHS-II cards will be best for running a single memory card set up with the maximum speed. The Sony A7III has pretty quick performance as long as you’re not using the second UHS-I memory card slot as backup.

V60 UHS-II cards are a great compromise for speed and performance. They still run quickly but cost a lot less.

For hybrid shooters that require video and stills that don’t need backup, a good way to save money is to shoot UHS-II in slot 1, using v90 or v60 depending on speed requirements, then use a UHS-II or UHS-I designed card like the Sony E card in slot two – where UHS-II cards can still be beneficial with their USB transfer speeds.

Here are some great SD card recommendations for the Sony A7III.

If I were buying cards today I personally would go with Sony G Tough or Sony M Tough in Slot 1, and Sony E in slot 2.

Best Accessories For The Sony A7III

Every Lens For The Sony A7III

In-Camera Speed Test

This chart displays Sony A7III SD card speeds tested in the camera.

There have been a lot of new memory cards since I last tested the A7III, so with some cards, I just used the previous generation speed. It should be at least the same or faster.

For the tests, I shoot a continuous burst using uncompressed RAW at ISO 100 with a shutter speed of 1/100.

I also test each card to check for 4k recording compatibility. Sony cameras don’t like some cards. For example, many Samsung cards even though they are U3 and SDXC, get rejected by the camera with an error that they are not U3 cards.

Sony A7III Camera Specs Buffer Questions

Sensor: 24MP Full-Frame Exmor R BSI CMOS Sensor
Processor: BIONZ X Image Processor & Front-End LSI
What Size Is The Buffer? 1.5GB estimated
What Memory Cards Are Compatible? UHS-I / UHS-II
Max Memory Card Capacity: Up to 1TB or larger.
How Long To Clear Buffer? 9:36
How Many Uncompressed Shots To Fill Buffer? 46

Sony A7 III – Amazon / Adorama / BHphoto

UHS-II vs. UHS-I Memory Cards In The Sony A7rIII

While the Sony A7 III takes advantage of UHS-II memory cards, speeds will be bottlenecked to the slowest memory card in the camera depending on how you’re using slot 1 and slot 2 with the recording modes.

Recording Mode Standard | Slot 1 | Auto Switch On

If you’re using Slot 2 as an overflow, then you will get UHS-II memory card speeds in Slot 1 until the card fills up. Then once the camera switches to Slot 2, speeds will slow down to the speed of the card in Slot 2 and that slot will only be able to produce UHS-I speeds.

With the Sony A7III, Auto Switch is turned off by default, so you will need to enable this yourself to gain this benefit.

Record Mode Simult. RAW+RAW

If you’re shooting Slot 1 and Slot 2 as a backup, then memory card write speeds will be throttled to the slowest card. If you shoot like this often, you may not see any benefit to using UHS-II cards.

Record Mode Simult. RAW+JPEG

We no longer test RAW+JPEG, but since JPEG files are smaller, you don’t see the same bottleneck as when you’re backing up with RAW to slot 2.

However, shooting RAW+JPEG does slow down the performance of the buffer significantly as it requires more processing as the cards are written to and this task is usually is not multithreaded.

Shooting Uncompressed RAW will make massive files and you will fill your buffer a lot quicker, but they won’t slow down your memory card write speeds.

Best Memory Cards 4k Video Sony A7 III

Shooting 4k video with Sony cameras does require some minimum specs for it to work.

Aside from some cards just not working (like Samsung), you will need a U3 memory card to shoot 4k video with the Sony A7 III.

Sony upgraded its firmware in 2016 so that you can now use SDHC memory cards for 4k video, however, you still need to use U3 memory cards. Here is a breakdown of some memory card stats and what all the numbers mean.

Class 10 / U1 – NO 4k!

Class 10 and U1 are one and the same. It has to do with the minimum write speeds a card is capable of. A Class 10 or U1 card should be able to sustain 10MB/s write speeds in any situation, sequential or random.

However, 4k will not work here.

U3 – 4k compatible

U3 is the minimum requirement for recording 4k video. It has a minimum performance speed of 30MB/s. So under any circumstance, it will be able to keep up with the 4k video bitrate demands regardless of whether the card is fragmented or not.

V30 – 4k compatible

V is the newest rating system. It also has to do with minimum write speeds. V30 is the same as U3, 30MB/s. It will also work for recording 4k video. Typically if a card is V30 it’s also U3 and meets Sony’s requirements.

V60 – 4k compatible

Even faster than V30 is V60. 60MB/s guaranteed minimum write speeds. The thing is with the V60 and V90, although the cards can perform with the guaranteed write speed of 60MB/s it doesn’t mean the camera can. Usually, a memory card’s performance is limited by the camera’s capabilities.

V90 – 4k compatible

Like V60 this means minimum speeds of 90MB/s. You mostly only see this on UHS-II cards.

What Size Memory Card For Sony A7III?

The Sony A7III can take memory cards of any size from 32GB or smaller, all the way up to 1TB or larger. You’ll want to start with a 64GB card to use the SDXC file system.

For Stills

I recommend 128GB.

For photographers shooting only still, I recommend buying a 128GB card. While I never use more than 128GB in a day of shooting, occasionally I’ll forget to clear off my camera before going out to shoot again, and having the extra memory is nice.

Also, if you decide to record video, the 128GB cards will allow you to record without breaking the video files up into 4GB chunks since 32GB cards can only be formatted with a 32-bit filesystem.

For Video

The memory card size for the Sony A7III when recording video depends on what format you are recording and how you plan on using the camera.

There are a few details you should note. Take a look at the max bitrates.

4k 24p / 30p Max Bitrate: 100Mbps

1080 24p / 25p / 30p / 50p / 60p Max Bitrate: 50Mbps

To get the maximum quality or 100Mbps at 24fps or 30fps with the Sony A7III you will need to record in 4k unless you want  100fps or 120fps then you can record 1080p with 100Mbps.

If you only want 1080p 24fps or 1080p 30fps, you will only get half the bitrate of 50Mbps. So even if you need 1080p, it’s better to record 4k and then scale down, which if done correctly in a 16-bit sequence will result in a 4:2:2 data compression. That’s the theory anyway.

Maximum Video Record Times by Memory Card Size

Here is a handy chart you can use to find the best-size memory card you’ll need for your recording format. Or how many minutes you can get with the different formats on with different size cards.

For video shooters and filmmakers, I recommend 128GB cards or higher. Now that there are 1TB SD cards available on the market, filmmakers that need to record a lot of video without the need to clear off their cards might find these larger cards useful.

Best Memory Cards Sony A7 III | Bottom Line

Going with the Sony G or Sony G Tough cards is your bet, but other cards have been working well for us, such as Delkin, Transcend, and Toshiba.

When using UHS-I cards, stick with U3 so that you can still record video and avoid Samsung and you’ll likely be free of any problems.