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CFexpress Source: en.wikipedia.org/wiki/CFexpress

CFexpress
A smaller rectangular memory card (left) next to a larger rectangular memory card (right)
CFexpress Type A (left) and Type B (right) cards
Media typeMemory card
StandardCFexpress 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 fromXQD 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]

History

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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

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Standard Version Launched Bus Speed (full-duplex)
CFexpress 1.0 2017 Q2 PCIe 3.0 x2 2.0 GB/s
2.0 2019 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)
4.0 2023 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 3.0 2010 Q2 UHS-I 0.1 GB/s
4.0 2011 Q1 UHS-II 0.3 GB/s
6.0 2017 Q1 UHS-III 0.6 GB/s
7.0 2018 Q2 PCIe 3.0 x1 1.0 GB/s
8.0 2020 Q2 PCIe 4.0 x2 4.0 GB/s
UFS Card 1.0 2016 Q2 UFS 2.0 0.6 GB/s
2.0 2018 Q4 UFS 3.0 1.2 GB/s
CFast 1.0 2008 Q3 SATA-300 0.3 GB/s
2.0 2012 Q3 SATA-600 0.6 GB/s
XQD 1.0 2011 Q4 PCIe 2.0 x1 0.5 GB/s
2.0 2014 Q1 PCIe 2.0 x2 1.0 GB/s

Form factors

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CFexpress supports the following card sizes.[6]

Form
Factor 		Dimensions
(mm) 		PCIe
Lanes
A 20.0 × 28.0 × 2.8 1
B 38.5 × 29.8 × 3.8 2
C 54.0 × 74.0 × 4.8 4

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]

  • A Sony CFexpress Type A reader and card
    A Sony CFexpress Type A reader and card
  • CFexpress Type B (left) next to an SD card (right)
    CFexpress Type B (left) next to an SD card (right)
  • A CFexpress Type B card with contacts visible
    A CFexpress Type B card with contacts visible
  • CFexpress Type B and SD slots on a Nikon Z8 camera
    CFexpress Type B and SD slots on a Nikon Z8 camera

See also

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Notes

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References

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  1. ^ a b "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. ^ a b c Williams, Matt (11 December 2023). "A Complete Guide to Memory Cards". PetaPixel. Retrieved 9 May 2025.