CompactFlash Association Announces CFexpress Family

The CompactFlash Association (CFA) announces the CFexpress family of high-performance removable storage based on PCIE and NVMe.

CFA has developed high-performance removable cards standards for the last 21 years with the CompactFlash, CFast, and XQD formats. It was formed in 1995 as the initial digital film format and continues to serve professional imaging and industrial markets where high performance and high-quality recording media is essential for high-speed capture and high-speed transfer into the workflow.

CFexpress is the next evolution in an open standard format for a set of applications, such as professional imaging, personal computing, servers, IoT and industrial. It differs from prior CFA standards in that CFexpress is a specification spanning multiple form factors and performance levels to match various market requirements while maintaining the same electrical/physical interface and memory/storage protocol. The CFexpress specification is under development within the CFA CFexpress Working Group.

CFA’s goals for CFexpress family are:

Unify the ecosystem around a removable storage specification that has longevity in the market
Provide a platform that scales with performance increases in the PCIe interface
Leverages the technologies and skillsets of the larger volume compute markets
Compatibility with the capture ecosystem and workflow tools.

CFexpress leverages the PCIE physical interface for higher performance based on the high-volume compute industry. PCIe CFA’s objective is to specify multiple removable storage devices that spans from two lanes architecture all the way up to eight lanes. With the current PCIE Gen 3 delivering maximum theoretical interface speeds of 1.0GB/s per lane, CFexpress would enable theoretical sequential speed of up to 8GB/s.

CFexpress also utilizes the low latency NVMe memory/storage protocol across all of the form factors. This enables compatibility with a set of ecosystem components, such as controllers, OS, capture devices and workflow modules. In imaging, compute and industrial applications, the use of PCIe /NVMe enables access to a range of open standard platforms consisting of mature and proven drivers. In addition, the CFexpress format also enable compatibility with the Thunderbolt interface which is also based on PCIe. Actual CFexpress products will vary in performance based on market requirements and protocol overheads.

Professional video data rate requirements are growing at an exponential rate exceeding the capabilities of existing open standard formats. 4K RAW video at 30fps requires 400-500MB/s of sustained performance not including any overhead to guarantee performance over the entire recording media. 4K RAW video at 120fps requires 1,600-2,000MB/s 4K RAW video at 240fps requires 3,200-4,000MB/s. Even in High-Quality I-Frame compression formats, the data rates quickly exceed 1.0GB/s at high frame rates.

Key feature and benefit:

Key Feature	Benefit
PCIe Gen 3 Interface	Provides a max theoretical interface speed of 1.0GB/s per lane of PCIe. This speed enhancement enables a new generation of higher performance cards to meet requirements for professional video recording.
Family of Form Factors	Provides multiple form factors to address multiple market segments with a unified physical interface and memory/storage protocol. 2 lane and 4 lane form factors will be the initial focus but anything from 1 lane to 8 lanes is possible. This provides a range of up to 8GB/s with PCIe Gen3.
NVMe	A storage interface designed from the ground up for NVM storage. The NVMe protocol features fixed length commands, an efficient queuing model, and very low non-cacheable PCIe accesses per command, delivering reduced I/O overhead and performance improvements in comparison to legacy storage device interfaces. NVMe is gaining popularity across various flash-based storage solutions and has driver support on all leading OSs.

Tom Ando, Canon, and CFA co-COB, said: “As the co-chairman of the CompactFlash Association I am pleased and excited to introduce CFexpress as CFA’s continues the tradition of performance leadership. The higher performance provided by CFexpress formats will further increase the capabilities and value for photographers, videographers, cinematographers, industrial, and compute applications. I am very pleased and proud to see the CFA creating standards that address new market requirements.“

Host and card manufacturers will be able to leverage the compute industry’s investment in PCIe and NVMe. Media manufacturers will be able to leverage high volume solid state disk (SSD) controller technology to serve the high performance requirements of this market. This format will have VPG (Video Performance Guarantee) capability with new VPG profiles at every increases performance levels. CFA’s goal for CFexpress is the development of a standard that can span many market segments and provide a stable and consistent format to fully leverage the industry’s R&D investments and less churn in the market of standardized and proprietary recording media formats.

Koichiro Kawamura, Nikon, and CFA co-COB said: “As the co-chairman of the CompactFlash Association I am also pleased and excited to introduce CFexpress. The specification is a family of form factors that can serve many market segments with a unified physical interface and unified memory/storage protocol. We are excited with the vision that CFexpress will unify the imaging and industrial ecosystems around formats that are easily compatible with the computing markets. CFexpress represents a unique opportunity to unify the market around truly open standard formats.”