The CFexpress card is currently world fastest memory card. The already announced Sony Tough CFexpress Type B memory card (code named CEB-G128) is based on a relatively new standard released by the Compact Flash Association. It will have the form factor of the XQD memory, but will offer up to 1,700 MB/s read and 1,480 MB/s write speeds. This makes it three times faster than the fastest Sony has released so far. There are rumors that 256 and 512 GB cards will be also manufactured.
And ProDigital also announced their CFexpress cards:
ProGrade Digital CFexpress cards provide read speeds up-to 1,600MB/s, and burst write speeds up-to 1,400MB/s. Two performance levels are available: Cobalt label: delivers minimum sustained write speed of 1,300MB/s; Gold label: delivers minimum sustained write speeds of between 100MB/s and 400MB/s depending on card capacity.
Currently, only Nikon cameras: Z6 & Z7, D5, D850, D500 announced that will support CFexpress cards.