CFexpress is a high-speed removable memory card format built on PCIe and NVMe for professional cameras shooting 4K, 6K, or 8K video.
The moment a camera starts recording 8K video or firing off rapid bursts, SD cards hit their ceiling. That’s the gap the CFexpress card fills: a PCIe/NVMe removable format that moves data several times faster than older card standards.
CFexpress comes from the CompactFlash Association, the same body behind CompactFlash, and it targets one job — keeping up with high-bitrate video and continuous burst shooting in advanced mirrorless, cinema, and pro video cameras.
How Is CFexpress Different From SD, XQD, And CFast?
CFexpress is its own standard, not a faster SD card or a rebranded XQD — Type B cards just happen to share XQD’s physical dimensions.
The format was announced in September 2016, with version 1.0 published in April 2017. Instead of older signaling methods, it runs on PCIe and NVMe — the same high-speed communication protocols used inside SSDs. That architecture is why even a single-lane CFexpress card can outpace the fastest SD cards by a wide margin.
XQD and CFast are the two formats people mix it up with. XQD cards look almost identical to CFexpress Type B, but a camera or reader built for XQD won’t read a CFexpress card without native support. CFast is a physically different card that uses SATA, and it has largely been superseded.
CFexpress Card Types: A, B, And C
Three CFexpress form factors exist — Type A, Type B, and Type C — and they differ in size, PCIe lane count, and top speed. The CompactFlash Association’s card type guide details the full spec for each.
Type B is the format most pro cameras use; Type A is the choice behind Sony’s Alpha lineup; Type C is the largest and least common in consumer gear. Type B’s dimensions match XQD’s, which fuels the confusion between the two standards. Type A is close to SD-card dimensions, while Type C is closer to a compact SSD in size.
| Form Factor | Dimensions | PCIe Lanes & Top Theoretical Speed |
|---|---|---|
| Type A | 20 x 28 x 2.8 mm | 1 lane, up to 1,000 MB/s |
| Type B | 38.5 x 29.8 x 3.8 mm | 2 lanes, up to 2,000 MB/s |
| Type C | 54 x 74 x 4.8 mm | 4 lanes, up to 4,000 MB/s |
Those are theoretical ceilings. The speeds you actually get depend on the camera, the card reader, and the host port, so real-world numbers always come in lower.
Which CFexpress Card Do You Need?
Match the card to your camera’s supported type first, then confirm the approved media list and compare sustained write speed before you buy.
Sony’s support documentation, for example, says Alpha cameras use CFexpress Type A, with Type B and Type C unsupported as of its April 2024 update. Most other major camera brands build their pro bodies around Type B, the most common professional format. A Type B camera will not accept Type A, and the reverse is true too.
Published speeds vary by model and capacity. SanDisk’s Extreme PRO Type B reaches 1,700 MB/s read and 1,400 MB/s write on the 512 GB version, while the 64 GB model drops to 800 MB/s write. Sony’s 128 GB Tough Type B card reads at 1,700 MB/s and writes at 1,480 MB/s. Lexar’s Professional GOLD Series Type B is rated up to 1,750 MB/s read and 1,500 MB/s write, with a 1,000 MB/s sustained write rate.
For video, sustained write speed matters more than peak read speed — that’s the number that keeps the recording buffer from filling mid-clip. Buying mistakes come down to three things: picking the wrong type, assuming XQD support means CFexpress support, and shopping by maximum read speed alone. The formula is simple: confirm the type, confirm the camera’s approved list, then buy the fastest sustained write you can afford. For current models worth buying, our tested roundup of the best CFexpress cards breaks down the top performers by capacity and sustained write speed.
FAQs
Is CFexpress The Same As XQD?
No. CFexpress Type B shares XQD’s physical size and connector layout, but the two are different standards. A camera or card reader must support CFexpress natively to read these cards — an XQD device won’t get you there. Always check the spec sheet for explicit CFexpress support before buying.
How Fast Is A CFexpress Card?
Speed depends on the type and the specific model. Type B cards commonly deliver 1,500–1,900 MB/s reads and 800–1,500 MB/s writes, while Type A tops out near 1,000 MB/s. Sustained write speed is what matters for long video clips, and it is always lower than the peak numbers on the box.
Do All Cameras Accept CFexpress Cards?
No. Only specific camera bodies support CFexpress, and most support a single type. Sony’s Alpha line uses Type A only, while many other pro cameras use Type B. Confirm the camera’s supported type and its approved media list before buying, because a Type B card won’t fit or work in a Type A camera.
References & Sources
- CompactFlash Association. “Card Types.” Official dimensions, lane counts, and theoretical speeds for CFexpress Type A, B, and C.