In context: CompactFlash Association (CFA) created the CFexpress standard in 2016 to leverage the PCI Express interface and NVM Express protocol for removable storage in the professional imaging industry. A recently announced upgrade to the technology pushes CFexpress card performance to SSD-class levels.
CFA has just introduced the CFexpress 4.0 standard, with new logical and physical specifications designed to greatly increase the theoretical performance of existing CFexpress 2.0 cards. CFexpress 4.0 removable media will retain backward compatibility with existing devices so that customers can preserve their earlier investments in the CFexpress ecosystem.
CFexpress 2.0 adopted PCIe Gen3 to reach a top full-duplex speed of 4 gigabytes per second. CFexpress 4.0 can "theoretically" double such performance thanks to the PCIe Gen4 interface, with a top throughput performance of 8 GB/s. CFA says that CFexpress 2.0 cards will still be available for purchase, providing enough "flexibility" in user choice when it comes to performance, power and size requirements - and money.
CFexpress 4.0 cards will also retain the same form factors adopted for the previous generation, with three different card types (Type A, Type B, Type C) featuring different sizes, number of PCIe Gen4 lanes supported, and speed & power requirements. Type A cards will offer a data throughput of 2 GB/s, while Type-C cards will go up 8GB/s by exploiting 4 PCIe Gen4 lanes. As usual, smaller cards can fit in larger card sockets with an adapter.
According to co-chairman of the CFA board Hiroshi Noda, the higher performance of CFexpress 4.0 removable media storage will support "current and future" needs of photographers, videographers and cinematographers. Professionals have standards, and they will now have access to higher resolutions, faster frame rates and richer color depths thanks to the faster PCIe Gen4 interface.
The three form factors offered by CFexpress 4.0 retain a "consistent" electrical, logical, and physical interface, CFA board member Hiroshi Machida remarked. Professionals can easily adapt the new standard in their devices, while host manufacturers can "significantly" reduce the development cycle.
CFexpress 4.0 specifications are available for CFA members only, with Canon, Sony, Nikon, Lexar, and other big corporations already on board. The CFA is also preparing a new VPG (Video Performance Guarantee) specification for higher sustained video recording applications, but such technology will be released at a later date.