Best Memory Cards for Sony A9 III: Buffer Tests & Capacity Guide

The Sony A9 III is a speed demon, capable of shooting at 120 fps in RAW. However, this incredible speed creates two major problems for memory cards: buffer clearing times and storage capacity.

If you shoot at 120fps, you can fill a standard memory card in seconds. Furthermore, while the camera supports both CFexpress Type A and SD UHS-II cards, SD cards will leave you stuck waiting for the buffer to clear while the action passes you by.

To help you choose, I have tested 52 memory cards in the Sony A9 III.

• For Video: S&Q slow motion in XAVC S-I (4K or HD) requires a CFexpress Type A card (VPG200 or higher); Sony doesn’t support SD cards for it. S&Q in XAVC HS or XAVC S needs at least a V90 SD card, and 600 Mbps All-Intra at normal frame rates also works on V90 SD.
• For 120fps Burst Shooting: You absolutely need CFexpress Type A cards. They clear the buffer significantly faster than SD cards, allowing you to get back to shooting instantly.
• For Capacity: Because 120 fps generates massive amounts of data, I recommend 160GB cards as a minimum, with 320GB or 640GB as the ideal sweet spot for sports and wildlife professionals.

Sony A9 III Recommended Memory Cards

Every CFexpress Type A card I tested in the A9 III wrote between 439 and 444 MB/s, so the camera is the bottleneck, not the card. Buy on price, warranty, and durability. The fastest SD cards top out around 223 MB/s in this body, about half the speed.

• Best value: Lexar Professional SILVER CF4.0. I haven’t run the new SILVER through the A9 III yet, but it writes about 640 MB/s in my reader tests, well above the camera’s ~445 MB/s ceiling, and it maxed out the A7V like every other CFxA card I tested.
• Fastest tested: Exascend Essential (444 MB/s), Lexar Gold (441 MB/s), and ProGrade Iridium CF4.0 (441 MB/s). They’re within 5 MB/s of each other, so buy whichever is cheapest.
• Pro (warranty and durability): Delkin BLACK or Sony TOUGH G CF4.0. The Delkin BLACK 80GB hit 440 MB/s and the line carries a lifetime warranty. The previous-generation Sony TOUGH G hit 434 MB/s; the current CF4.0 version adds a 5-year warranty and an IP57 rating.
• If you need SD (V90): PNY EliteX-PRO90 or Angelbird AV PRO V90 MK2. Both hit 223 MB/s, the fastest SD results in my A9 III tests. V90 covers 600 Mbps All-Intra and S&Q in XAVC HS and XAVC S.
• Budget (stills and H.265): SanDisk Extreme PRO V60 256GB–1TB. 177 MB/s, the fastest V60 card in my A9 III tests. Skip V60 for 600 Mbps All-Intra and S&Q.

Sony A9 III Memory Card Benchmarks

Here are the benchmarks for all the cards I’ve tested. I fill the camera buffer with a fast burst, then calculate the amount of data written per unit time as the card clears.

The Sony A9 III has a buffer of about 5GB.

The Reality of 120fps & Capacity

Best Memory Card Size for Sony A9 III (The 120fps Problem)

When shooting at 120 fps, the Sony A9 III generates roughly 5-8GB of data every few seconds, depending on your compression settings. This changes the math on what memory card size you should buy.

640GB+ Cards: Ideal for hybrid shooters who want to switch between high-bitrate video and high-speed bursts without managing multiple cards.

160GB – 320GB Cards: This is the new standard for the A9 III. A 160GB card offers a safe balance, but if you are shooting an all-day event, a 320GB card will save you from constantly swapping cards in the field.

80GB Cards: In 120fps burst mode, an 80GB card can fill up in under a minute of continuous shooting. These are generally too small for dedicated sports photographers.

CFexpress 4.0 vs 2.0

Can you use CFexpress 4.0 Cards in the Sony A9 III?

Yes, you can use CFexpress 4.0 Type A cards in the Sony A9 III, and they are fully backward compatible.

However, it is important to note that the Sony A9 III utilizes a CFexpress 2.0 interface. This means you will not see a write-speed benefit in the camera when using a 4.0 card versus a fast 2.0 card; both will hit the camera’s internal bottleneck.

Why buy CFexpress 4.0? The main advantage is offloading speed. If you use a CFexpress 4.0 card reader, you can transfer your footage to your computer twice as fast as with a 2.0 card reader. When you are dumping 500GB of 120fps burst shots after a shoot, this can save you 20-30 minutes of waiting time.

Video Specs & VPG Requirements

Video Specs: When Do You Need VPG200 or VPG400?

For most video modes, including standard 4K 60p, the Sony A9 III is very forgiving. However, if you want to shoot the highest quality slow motion, you will hit a hard wall with SD cards.

1. XAVC S-I 4K (Standard 60p Recording)

• Bitrate: 600Mbps (approx. 75MB/s)
• Compatible Cards: CFexpress Type A OR SD Cards (V90 Only)
• The Reality: You can use a high-quality V90 SD card for the A9 III’s highest-quality “standard” recording modes (All-Intra 600 Mbps). The camera will not stop you. However, V60 cards are not fast enough for this mode.

2. S&Q Mode (The “Trap” for SD Users)

The rules change when you switch the dial to S&Q (Slow & Quick) to shoot 4K at 120 fps in XAVC S-I for slow motion.

• Bitrate: Up to 1200Mbps (approx. 150MB/s) in 4K and 890Mbps in HD. The menu bitrate applies to the playback frame rate, so shooting 120fps for 24p or 60p playback writes several times that to the card.
• Requirement: CFexpress Type A (VPG200)
• Why: 1200Mbps (150MB/s) is well above the 90MB/s a V90 card guarantees, and Sony doesn’t support SD cards for S&Q in XAVC S-I. If you try to select this mode with an SD card inserted, the option will be grayed out in the menu.

Important: S&Q in XAVC HS and XAVC S is less demanding, but it still writes far more than the menu bitrate: Sony rates it at up to 500 Mbps (XAVC HS 4K) and 560 Mbps (XAVC S 4K). That’s why Sony requires a V90 SD card or a CFexpress Type A card for it. V60 cards won’t cover S&Q, even in H.265.

3. Do You Need VPG400?

You will see many newer cards (especially CFexpress 4.0 cards like the OWC Atlas or ProGrade Gold) sporting a VPG400 logo.

Should you get it? Yes. VPG400 guarantees sustained write speeds of 400 MB/s. This offers significantly more “headroom” than VPG200, ensuring your camera never stops recording due to thermal throttling or card fragmentation during long takes.

Is it required? No. The Sony A9 III currently only requires VPG200 to unlock all recording modes.

Sony A9 III Memory Cards Bottom Line

Choosing memory cards for the Sony A9 III is pretty straightforward. It’s a high-end camera, so go with high-end cards. The CFexpress Type-A cards have now come down in price to the point where SD UHS-II no longer makes sense unless you need a v60 card for casual video at lower bitrates. You cannot use a v60 card for the 600Mbps H.264 bitrate, but they work great for the HEVC recording modes at normal frame rates. S&Q slow motion needs a V90 card in XAVC HS or XAVC S, and a CFexpress Type A card in XAVC S-I.

Some great budget cards, like the Lexar Silver CFexpress Type A, can also be a great option for video or casual shooting.