CFexpress
Memory Cards · 7 specs
Direct Answer
CFexpress is an ultra-high-speed removable solid-state storage media standard developed by the CompactFlash Association (CFA). Built directly on the PCI Express (PCIe Gen 3/Gen 4) physical bus and NVM Express (NVMe) command set, it is the dominant storage medium for high-end professional digital cinema, mirrorless photography, and broadcast video.
Source: CompactFlash Association (CFA) CFexpress 1.0 / 2.0 / 4.0 Specifications · Last reviewed Aug 28, 2026
Specs
| Governing Body | CompactFlash Association (CFA) |
| Underlying Storage Architecture | PCI Express (PCIe Gen 3 / Gen 4 / Gen 5) + NVM Express (NVMe v1.3/1.4) |
| Type A Dimensions & Bus | 20.0 × 28.0 × 2.8 mm | 1-lane PCIe (1 GB/s PCIe 3.0 / 2 GB/s PCIe 4.0) |
| Type B Dimensions & Bus | 38.5 × 29.6 × 3.8 mm | 2-lane PCIe (2 GB/s PCIe 3.0 / 4 GB/s PCIe 4.0) |
| Type C Dimensions & Bus | 54.0 × 72.0 × 4.4 mm | 4-lane PCIe (4 GB/s PCIe 3.0 / 8 GB/s PCIe 4.0) |
| Type B XQD Compatibility | Physically identical exterior shell to Sony XQD (host backward-compatible via firmware) |
| Operating Power Tiers | Up to 1.7W (Type A) / Up to 3.0W (Type B) / Up to 6.0W (Type C) |
The Three Physical Form Factors
The CFA standardized three discrete form factors to address different device sizes:
- Type A (Compact): Slightly smaller than a standard SD card with 1 PCIe lane. Exclusively popularized by Sony in Alpha cameras (A1, A7 IV, A7S III, FX3) utilizing combo slots that accept either SD or CFexpress Type A.
- Type B (Mainstream Pro): Uses 2 PCIe lanes and shares the exact mechanical footprint and 44-pin connector of legacy Sony/Nikon XQD cards. Adopted by Canon (EOS R5), Nikon (Z6/Z7/Z8/Z9), Panasonic, and Phase One.
- Type C (Cinema/Datacenter): Uses 4 PCIe lanes delivering up to 4–8 GB/s for high-end digital cinema rigs and portable computing.
CFexpress 4.0 and PCIe Gen 4 Scaling
Ratified in 2023, the CFexpress 4.0 specification doubled throughput across all three form factors by adopting PCIe Gen 4 without changing pin layouts or physical dimensions. This allows Type B cards to achieve 4,000 MB/s (4 GB/s) read/write speeds, easily sustaining uncompressed 8K 60fps and 12K RAW video capture directly in-camera.