The new CFexpress standard will be twice as fast
The CompactFlash Association has announced the new CFexpress 4.0 standard.
The new standard will be available in Type A, Type B and Type C varieties, and will all offer double the speed when compared to the current CFexpress 2.0 specification.
That means CFexpress Type A – currently only used by Sony cameras – will double in speed from 1GB/sec up to a theoretical 2GB/sec. CFexpress Type B, such as what's found in Canon and Nikon devices, will increase from 2GB/sec to a 4GB/sec theoretical maximum.
CFexpress Type C, which hasn't been adopted by any major camera manufacturers yet, will increase from 4GB/sec to 8Gb/sec.
It's worth noting that even the current fastest CFexpress cards on the market don't achieve the maximum speeds, so you can take all this with a grain of salt.
That said, the benefits of the faster write speeds are obvious for sports and wildlife shooters, who would, if camera manufacturers allow writing at the theoretical maximum speeds, be able to shoot faster for longer.
Additionally, the CompactFlash Association says that the new cards will also be backwards compatible with CFexpress 2.0 compatible devices, as they will share the same form factor. It means if you have a bunch of 2.0 cards currently, you won't need to upgrade anytime soon, as they will continue to work in any future cameras that utilise the CFexpress 4.0 standard.
You can read the full announcement on the CompactFlash Association website.