CFexpress

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CFexpress
CFexpress logo.svg
Biwin CFexpress Type A and Type B cards at Computex 2025.jpg
CFexpress Type A (left) and Type B (right) cards
Media type Memory card
Standard CFexpress standard
Developed byCompactFlash Association
Dimensions
Type A
20.0×28.0×2.8 mm (0.79×1.10×0.11 in)
Type B
38.5×29.8×3.8 mm (1.52×1.17×0.15 in)
Type C
54.0×74.0×4.8 mm (2.13×2.91×0.19 in)
Extended from XQD card
Released2017

CFexpress is a standard for removable media cards by the CompactFlash Association (CFA). The standard uses the NVM Express protocol over a PCIe interface. 3 different form factors are available, with 1 to 4 PCI-E lanes available. [1]

Contents

History

On 7 September 2016, the CompactFlash Association announced the CFexpress standard, with specifications based on the PCI Express interface and NVM Express protocol. [1]

On 18 April 2017 the CompactFlash Association published the CFexpress 1.0 specification. [2] Version 1.0 will use the XQD form-factor (38.5 mm × 29.8 mm × 3.8 mm) with two PCIe 3.0 lanes for speeds up to 2 GB/s. NVMe 1.2 is used for low-latency access, low overhead and highly parallel access.

On 13 June 2017, Delkin introduced the first CFexpress cards based on the CFexpress 1.0 specification. [3]

The CFexpress 2.0 standard was announced on 28 February 2019. It features two new card formats - a more compact Type A with one lane, and a larger Type C with four lanes. Existing cards were designated as Type B. The NVM Express protocol was upgraded to 1.3. [4]

The CFexpress 4.0 standard was announced on 28 August 2023. CFexpress 4.0 supports up to four PCIe 4.0 lanes, at 2 GB/s per lane - twice as fast as CFexpress 2.0. The NVM Express protocol was upgraded to 1.4c. [5]

Comparison

StandardVersionLaunchedBusSpeed (full-duplex)
CFexpress1.02017 Q2PCIe 3.0 x22.0 GB/s
2.02019 Q1
  • PCIe 3.0 x1
  • PCIe 3.0 x2
  • PCIe 3.0 x4
  • 1.0 GB/s (Type A)
  • 2.0 GB/s (Type B)
  • 4.0 GB/s (Type C)
4.02023 Q3
  • PCIe 4.0 x1
  • PCIe 4.0 x2
  • PCIe 4.0 x4
  • 2.0 GB/s (Type A)
  • 4.0 GB/s (Type B)
  • 8.0 GB/s (Type C)
SD 3.02010 Q2UHS-I0.1 GB/s
4.02011 Q1UHS-II0.3 GB/s
6.02017 Q1UHS-III0.6 GB/s
7.02018 Q2PCIe 3.0 x11.0 GB/s
8.02020 Q2PCIe 4.0 x24.0 GB/s
UFS Card 1.02016 Q2UFS 2.00.6 GB/s
2.02018 Q4UFS 3.01.2 GB/s
CFast 1.02008 Q3 SATA-3000.3 GB/s
2.02012 Q3SATA-6000.6 GB/s
XQD 1.02011 Q4PCIe 2.0 x10.5 GB/s
2.02014 Q1PCIe 2.0 x21.0 GB/s

Form factors

CFexpress supports the following card sizes. [6]

Form
Factor		Dimensions
(mm)		PCIe
Lanes
A20.0 × 28.0 × 2.81
B38.5 × 29.8 × 3.82
C54.0 × 74.0 × 4.84

The larger form factors have more electrical contacts, allowing more PCIe lanes to be used.

Type A is similar in size to an SD card. As of 2023, Sony is the only camera manufacturer that has adopted CFexpress Type A, using it in some of its Sony α cameras. All Sony CFexpress slots also support UHS-II SD cards. [7]

Type B is the most popular CFexpress form factor, and is used by several camera manufacturers, including Canon, DJI, Nikon, Panasonic, and Red. It has the same size and contacts as an XQD card, allowing a single card slot to accept both XQD and CFexpress Type B cards. Some older cameras with XQD slots have received firmware updates to allow use of a CFexpress Type B card in its XQD slot. [7]

As of 2023, no devices have implemented CFexpress Type C, and neither cards nor cameras are available. [7]

See also

Notes

    References

    1. 1 2 "CFA 5.1 Press Release" (PDF). 7 September 2016. Archived from the original (PDF) on 21 December 2016. Retrieved 12 April 2025.
    2. ↑ "CFexpress 1.0 Press Release" (PDF). 18 April 2017. Archived from the original (PDF) on 12 December 2017. Retrieved 12 April 2025.
    3. ↑ "Industrial CFexpress 1.0 and Industrial CFX 1.0 Cards". Delkin Industrial. Retrieved 29 June 2017.
    4. ↑ "The CompactFlash Association Announces CFexpress® 2.0 Specification" (PDF). 1 March 2019. Archived from the original (PDF) on 19 May 2023. Retrieved 12 April 2025.
    5. ↑ "2023-08-21 CFexpress 4.0 Press Release - FINAL CLEAN" (PDF). CompactFlash Association. The CompactFlash Association. 28 August 2023. Archived (PDF) from the original on 5 April 2025. Retrieved 12 April 2025.
    6. ↑ "CFexpress 2.0 Specification Introduces two New Form Factors" . Retrieved 23 August 2020.
    7. 1 2 3 Williams, Matt (11 December 2023). "A Complete Guide to Memory Cards". PetaPixel. Retrieved 9 May 2025.
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