Modern mirrorless cameras generate massive data streams with high resolutions, rapid burst modes, and top-tier video (Raw, 8K). For such demands, CFexpress cards exceed the speed of SD cards, providing reliable, sustained write performance. This article details how the format works, why it helps with large data loads, and what to consider when selecting a CFexpress solution.
Why CFexpress Matters
- Beyond SD’s Limits
SD cards typically max out at around 230 MB/s write speeds—often insufficient for extended bursts or high-bitrate video. CFexpress easily quadruples or quintuples that, minimising slowdowns during photo sequences or 8K filming. - Handling Large, Sustained Throughput
CFexpress can maintain write rates of hundreds of MB/s consistently, meaning you won’t see the dreaded buffer choke in cameras. Some cards boast 1.4 GB/s or higher sustained writes, which can handle intense workloads like uncompressed RAW bursts or 8K RAW video. - Various Series & Speeds
Many manufacturers offer two (or more) CFexpress lines: an ultra-fast pro option (with high sustained writes) and a more budget-friendly one (lower speeds but more capacity). Check the crucial “sustained write” figure, not just the peak number on the label.
CFexpress Types and Versions
- Type B vs. Type A
CFexpress Type B is the de facto standard for Canon, Nikon, and others, while Sony uses Type A in some Alphas. Type B cards are physically larger, can reach higher speeds, and are more widely available. - VPG Ratings
“VPG 200” or “VPG 400” on a card indicates guaranteed minimum continuous write speeds of 200 MB/s or 400 MB/s—useful for 4K/8K video. Still, if your camera pushes beyond that (some pro bodies hit 700+ MB/s), you’ll need an even faster solution. - 4.0 Standard
CFexpress 4.0 doubles maximum throughput from the 2.0 spec, aiming for up to 4 GB/s. Few devices support that rate today, but it’s on the horizon, ready for next-gen cameras and card readers.
Card Selection Tips
- Sustained Write vs. “Up to”
A high peak figure (like 1,700 MB/s) might not hold over sustained bursts. Seek cards advertising real continuous speeds, especially if you shoot long RAW sequences or high-bitrate video. - Capacity vs. Speed
Lower-capacity cards may have slower sustained writes than higher-capacity siblings in the same line. Example: A brand’s 128 GB might do only 200 MB/s, but 256 or 512 GB variants in the same family can exceed 500+ MB/s. - Compatibility
Check your camera maker’s recommended or tested list. Some brands (like Fujifilm, Canon, Nikon) officially verify certain CFexpress lines to ensure stable 8K or fast RAW shooting. - Heat & Reliability
CFexpress cards are essentially tiny SSDs, which can heat up under intense writes. In extreme continuous shooting, the card or camera might throttle. Seek well-reviewed brands known for thermal stability.
Reader & Workflow
- Card Readers
To exploit CFexpress’s speed, you need a matching reader with a fast interface—e.g., USB 3.2 Gen 2×2 or Thunderbolt 3/4. Mac, PC, or standalone readers can easily exceed 1 GB/s, but subpar hardware or cables hamper results. - Sustained vs. Occasional
If your typical shoot rarely hits the camera’s buffer, you might get away with a slightly slower CFexpress. But pro sports, wildlife, or cinematographers producing multi-gigabyte sequences benefit hugely from a top-tier sustained card.
Conclusion
CFexpress is a leap forward in memory card tech, catering to modern cameras that churn out gigabytes of data per second. While these cards can cost more than SD, the rewards—in faster bursts, reliable 8K footage, and fewer buffer hiccups—make them essential for advanced photography and video. Just pay close attention to a card’s sustained write rating to ensure it matches your camera’s throughput, and pick a robust card reader for your post-processing workflow.