The Sony A7IV is a hybrid powerhouse, but its high-bitrate video modes (like 4K 60fps in XAVC S-I) and deep photography buffers can easily choke older memory cards. If you are seeing the dreaded “Writing to memory card…” message or cannot select specific video settings, your card is likely the bottleneck.
This guide breaks down exactly what you need to unlock the full potential of your camera, distinguishing between the new CFexpress Type A standard and the familiar SD UHS-II format.
The Cheat Sheet: Top 3 Recommendations
If you just want to know what to buy, here are the top performers tested for the A7IV.
| Category | Card Name | Write Speed | Approx. Price (128GB/160GB) |
| Best Speed (Pro) | Sony CFexpress Type A (CEA-G) | 700 MB/s | ~$350 (160GB) |
| Best Overall (SD) | Sony SF-G TOUGH V90 SD | 299 MB/s | ~$180 (128GB) |
| Best Value | Kingston Canvas React Plus V90 | 260 MB/s | ~$100 (128GB) |
Technical Explanation: CFexpress Type A vs. SD Cards
The Sony A7IV features two card slots. Slot 1 is a dual-format slot that accepts either a standard SD card or a CFexpress Type A card. Slot 2 accepts only SD cards.
- SD UHS-II (V90): These are sufficient for 95% of users. A V90-rated SD card allows you to record almost all video formats, including 4K 60fps in XAVC S-I (Intra) which hits bitrates of 600Mbps.
- CFexpress Type A: These are significantly smaller and faster than SD cards. You only strictly need one if you shoot in specific S&Q (Slow & Quick) modes (like 4K 60p slow-motion playback) or if you are a sports/wildlife photographer who needs to clear the image buffer instantly.
Key Takeaway: If you shoot standard 4K 60fps video, a V90 SD card is enough. If you want an “unlimited” photo buffer or S&Q reliability, get CFexpress Type A.
Deep Dive Reviews
1. Sony CFexpress Type A (CEA-G Series) – The Speed Demon
Verdict: The ultimate card for professionals who cannot afford to wait.
This is the native card designed for Sony’s latest Alpha bodies. With a write speed of 700 MB/s, it is over twice as fast as the best SD cards. In practical terms, this means the A7IV’s buffer clears almost instantly. You can shoot compressed RAW bursts indefinitely without the camera freezing up. It is also required to unlock specific high-bitrate Slow & Quick motion settings that V90 SD cards technically cannot support. The downside is the “Sony Tax”—it is expensive per gigabyte.
2. Sony SF-G TOUGH UHS-II SD (V90) – Best Overall SD
Verdict: The most reliable, rugged SD card on the market.
If you don’t want to invest in the CFexpress ecosystem yet, this is the best SD card you can buy. The “TOUGH” specification means it is built from a single piece of molded plastic with no write-protection switch and no fragile ribs, making it virtually unbendable and waterproof. It maxes out the SD interface with write speeds up to 299 MB/s. It handles the A7IV’s 600Mbps 4K 60p video codec with ease and offers excellent reliability for wedding and event shooters who fear physical card failure.
3. Kingston Canvas React Plus UHS-II (V90) – Best Value
Verdict: Flagship performance for half the price.
The Kingston Canvas React Plus is widely considered the “insider’s secret” in the camera world. It consistently performs neck-and-neck with the Sony TOUGH cards in speed tests but costs significantly less—often around $100 for 128GB compared to Sony’s ~$180. It is fully V90 rated, meaning it will unlock all the same standard video modes as the expensive Sony cards. While it lacks the physical ruggedness of the TOUGH series, it often includes a free UHS-II card reader in the box, adding even more value.
Buying Advice: The Verdict
- Buy the Kingston Canvas React Plus if you are a hybrid shooter on a budget. It unlocks 4K 60fps recording without breaking the bank.
- Buy the Sony SF-G TOUGH SD if you are a professional photographer (Weddings/Events) who prioritizes physical durability and data safety above all else.
- Buy the Sony CFexpress Type A only if you rely heavily on Burst Mode (sports/wildlife) or need the specific S&Q slow-motion video modes.
Sony A7 IV Buffer Test: CFexpress vs SD
This video directly compares the buffer clearing times of CFexpress Type A cards against SD UHS-II cards specifically on the Sony A7IV, visualizing the performance gap discussed above.
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