Sony A9 SD Memory Card Requirements

The Sony A9 uses SD memory cards. It can use cards with a maximum capacity of 2TB.

It was released in 2017, and the SD card compatibility is complicated.

Slot 1 is compatible with UHS-II SD cards. Those cards will be faster than a UHS-I card, but more expensive.

Slot 2 is not compatible with UHS-II cards. You can save money by buying a UHS-I card.

Sony PRO Duo memory cards can be used in Slot 2. I would not recommend them as they are discontinued. Additionally, SD cards are faster, cheaper, and have larger storage capacities.

Sony A9 Lens Recommendations

Sony A9 SD Card Compatibility

The Sony A9 is compatible with the SD, SDHC, and SDXC standards. Each of those standards use a different file system.

Check to make sure the camera has the latest firmware.

The newest SDUC (Secure Digital Ultra Capacity) cards will not work with the A9. They are too large.

• SD (Secure Digital) - 128MB to 2GB. (FAT12/16)
• SDHC (Secure Digital High Capacity) - 4GB to 32GB. (FAT32)
• SDXC (Secure Digital eXtended Capacity) - 64GB to 2TB. (exFAT)
• SDUC (Secure Digital Ultra Capacity) - 4TB to 128TB. (exFAT)

Image Capacity

Here’s the approximate image capacity for high-quality JPEGs from the 24.2 megapixel sensor:

• 32GB - 4,240
• 64GB - 8,480
• 128GB - 16,960
• 256GB - 33,920
• 256GB - 67,840

Card Speed Class

Class rating is determined by sustained write speed. The rating will be shown as a number inside of a C on the label.

For example, as card that could write data at 5MB/s would get a Class 4 rating.

Class 10 card are likely much faster than 10MB/s. That’s why there are additional ratings for high resolution video.

• Class 2 - 2MB/s
• Class 4 - 4MB/s
• Class 6 - 6MB/s
• Class 8 - 8MB/s
• Class 10 - 10MB/s or faster

Dual Card Slots

Do Both Memory Card Slots Need to be Used?

No, the Sony A9 will work with a card in only one slot.

Using both card slots enables the following options:

• Mirror the Cards. Both memory cards will have the same files written to them.
• Overflow. Once the first card is full, files will be written to the second card.
• RAW+JPEG. Raw files will be written to one card and JPEGs of the same images will be written to the second card.

Do SD cards need to match?

No, the SD cards do not need to be the same. They do not need to be made by the same manufacturer. Cards can be different capacities.

Having matching cards helps to prevent compatibility problems from one card being too slow.

Recommended SD Cards

Use a UHS-II card in slot 1.

Any new card will be fast enough for photos and video. The video bit rate isn’t fast enough to require an expensive SD card.

Don’t pay for a super fast card. The A9 can’t write data that fast.

Don’t buy a UHS-II card. The A9 doesn’t have the hardware to take advantage of the extra speed. A V90 UHS-II card will just be a waste of money.

Don’t buy a used card. There is no way to find out how much life is left.

Affiliate Advertising Disclosure

Outside the Shot is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. As an eBay Partner, I may be compensated if you make a purchase. I also participate in affiliate advertising programs with KEH and Adorama. More can be found on the Affiliate Disclosure page.

SanDisk Extreme PRO SDXC V60 UHS-II 128GB

• Record 6K and 4K UHD
• Quickly clear image buffer
• 280MB/s Transfer Speed

Lexar Professional SDXC V60 UHS-II 128GB

• Record 4k Video
• 256GB Capacity Available
• 250MB/s Transfer Speed

PNY EliteX-PRO60 SDXC V60 UHS-II 256GB

• Record 4k UHD Video
• 512GB Capacity Available
• 280MB/s Transfer Speed

Lexar Professional 128GB

• UHS-I, U3, and V30 Speed Rating. Can sustain 30MB/s write speeds.
• Excellent choice for photos.
• Capable of recording 4k Video.
• Larger capacities are available.

SanDisk Ultra 64GB

• UHS-I, U1, and Class 10 Speed Rating. Can sustain 10MB/s write speeds.
• Excellent choice for photos.
• Capable of recording Full HD (1920x1080) Video.
• Inexpensive with more than good enough performance.
• Larger capacities are available for a reasonable price.

PNY Elite-X 128GB SD Card

• UHS-I, U3, V30, and Class 10 Speed Rating. Can sustain 30MB/s write speeds.
• Good for burst shooting photos and recording 4K video.
• Larger capacity cards are available.
• Reliable & Durable: Magnet Proof, Shock Proof, Temperature Proof, Waterproof.

SanDisk Extreme PRO 128GB

• Comparatively expensive for faster read speeds.
• UHS-I, U3, V30, and Class 10 Speed Rating. Can sustain 30MB/s write speeds.
• Only makes sense for professional use or if you need the largest storage capacity available.
• Temperature-proof, waterproof, shock-proof, and X-ray-proof.

Sony A9 PRO Duo Memory Stick Compatibility

The Sony A9 can use PRO Duo and PRO-HG Duo Memory Sticks. Those are a proprietary memory card format that Sony has discontinued.

PRO-HG are the fastest with read speeds up to 50MB/s and a 15MB/s minimum write speed. The largest capacity available is 64GB. Expect to pay at least twice as much as an SD card.

If you have a Memory Stick, go ahead and use it.

I would not recommend purchasing a PRO Duo card. SD cards are easier to find, less expensive, come in larger capacities, and are compatible with more devices.

Ultra High Speed (UHS)

The Ultra High Speed bus (UHS) is available with SDHC, SDXC, and SDUC memory cards.

There are three different specifications that increase with maximum transfer rates.

UHS ratings are shown on a card label as a Roman number I, II, or III. Product listing will prominently display the rating.

• UHS-I - Maximum transfer rate of 104 MB/s
• UHS-II - Maximum transfer rate of 312 MB/s
• UHS-III - Maximum transfer rate of 624 MB/s