CFexpress is a standard for removable media cards proposed by the CompactFlash Association (CFA). The standard uses the NVM Express protocol over an PCIe 3.0 interface with 1 to 4 lanes where 1 GB/s data can be provided per lane. There are multiple form factors that feature different PCIe lane counts. One of the goals is to unify the ecosystem of removable storage by being compatible with standards already widely adopted, such as PCIe and NVMe. There already is a wide range of controllers, software and devices that uses these standards, accelerating adoption.
History
On 7 September 2016, the CompactFlash Association announced CFexpress. The specification would be based on the PCI Express interface and NVM Express protocol.
On 18 April 2017 the CompactFlash Association published the CFexpress 1.0 specification. 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. In February 2018, they released benchmarks, with sample units introduced in the second quarter of 2018, and production scheduled for the third quarter.
The CFexpress 2.0 standard was announced on 28 February 2019. It features two new card formats ("type A", one lane, more compact and "type C", four lanes, bigger and thicker, up to 4 GB/s), with the existing cards designated as "type B". The NVM Express protocol was upgraded to 1.3.
CFexpress 2.0 type B Gen4 Cards are basically already available in the form of the Seagate Storage Expansion Card for Xbox Series X|S, which are mechanically incompatible to most slots because of their lengthened housing.
The CFexpress 4.0 standard was announced on 28 August 2023. The NVM Express protocol was upgraded to 1.4c.
Comparison
Form Factors
CFexpress supports the following card sizes. The second column lists the oldest CFexpress version that includes the form factor.
The larger form factors have more electrical contacts, allowing more PCIe lanes to be used. Form factor B has the same size and contacts as an XQD card, allowing a single card slot to accept both XQD and CFexpress-B cards.
Compatible devices
Cards
Delkin
On 13 June 2017, Delkin introduced the first CFexpress cards, which were on the CFexpress 1.0 specification. The cards have a XQD form factor and use two PCIe 3.0 lanes. They come in 32 GB, 64 GB, 128 GB and 256 GB capacities.
More details on Delkin's CFexpress cards were revealed in February 2018. The cards should be able to be read from and written to with respectively up to 1.6 GB/s and up to 1.0 GB/s benchmarked with CrystalDiskMark 5.2.1. Sample units will be available in Q2 2018 and production is scheduled for Q3 2018.
Delkin's 512 GB Power CFexpress Type B card was reviewed along with several others in the early fall of 2020. Camnostic.com rated it the recommended buy due to generally doing well in its tests, but also because it was the cheaper of the alternatives. The article mentioned a firmware upgrade to address compatibility with the Canon EOS R5 camera in late September 2020.
ProGrade Digital
ProGrade Digital announced it would begin production and sale of CFexpress cards in 2018 with the Type-B form-factor (the same as XQD). The 1 TB CFexpress card that ProGrade Digital showed at the Spring NAB show in 2018 demonstrated 1,400 Mbyte/sec read speed and over 700 Mbyte/sec burst write speed. This demonstration was performed using a Thunderbolt 3 CFexpress/XQD reader on a MacBook Pro computer.
Apacer
On 11 December 2018, Apacer announced its first CFexpress card, the PV130-CFX.
Wise Advanced
On 7 April 2019, Wise Advanced announced it was producing CFexpress cards with 512GB, 256GB, and 128GB capacities, as well as a CFexpress Card Reader, all using CFexpress Type B.
Readers
CFexpress Type A
Sony MRW-G2
CFexpress Type B
BLACKJET TX-1CXQ
Sony MRW-G1. Compatible with both XQD and CFexpress Type B cards. Delkin CF Express Reader (DDREADER-54) SanDisk Professional PRO-READER CFexpress Angelbird CFexpress Card Reader MK2 | Type B Lexar Professional CFexpress Type B USB 3.1 Reader Lexar Professional CFexpress Type B USB 3.2 Gen 2×2 Reader
Parts
On October 2, 2017, Rego Electronics announced CFexpress host connectors and card cardkits, parts that manufacturers can use for their CFexpress devices and cards.