CompactFlash Association (CFA), the organization responsible for professional removable media specifications such as CompactFlash?, CFAST?, XQD?, and CFexpress? announces the release of the CFexpress 4.0 logical and physical specifications increasing the performance of the existing CFexpress 2.0 specifications while maintaining backward compatibility targeting the professional imaging and industrial markets requiring high-performance data capture and transfer.

CFexpress 4.0 is an evolutionary specification riding on the great success of CFexpress 2.0 employing the industry standard PCI Express? (PCIe) Gen4 bus and NVM Express (NVMe) 1.4c logical interface for even higher performance and efficient NAND Flash access.  With its three form factors, CFexpress 4.0 continues to support diverse performance levels to match various market requirements maintaining consistent electrical, logical, and physical interfaces while setting realistic power consumption targets for wider adoption of the CFexpress 4.0 for battery-powered applications in the imaging and industrial markets.  Utilizing widely adopted open standards allow the use of established development platforms saving development time, cost, and effort.

CFexpress was developed in 2016 with the charter to become a removable media standard that can span various vertical market segments providing a stable and future-proof platform with economies of scale.  Since then, the standard has been widely adopted by the imaging and industrial market segments.


With the adoption of PCIe Gen4 in CFexpress 4.0, the media cards can theoretically achieve double the throughput performance compared to PCIe Gen3 of CFexpress 2.0 while maintaining backward compatibility.  CFexpress 4.0 along with CFexpress 2.0 shall provide flexibility in the choice of performance, power, and size requirements for target host devices based on their requirements.

Form Factor

The three card types – Type A, Type B, and Type C – support different host form-factor and performance requirements while maintaining a consistent electrical, logical, and physical interface.  The mechanical dimensions of each card type are specified allowing adaptor cards for smaller card types to fit into larger card sockets.  Metal lids provide physical robustness to withstand use in harsh environments while providing easier thermal management for hosts.


CFexpress 4.0 allows seamless migration from CFexpress 2.0 by utilizing the same underlying bus and logical interfaces of PCIe and NVMe while maintaining the exact same form factors.  This allows the preservation of earlier investments made in CFexpress cards.

CFA is also preparing a new specification for VPG (Video Performance Guarantee) for higher sustained video recording which shall be released in the near future.

The new CFexpress 4.0 specifications are available for CFA members only.