The SD Association has announced a leap in transfer rates with the new SD Express 8.0 (SD8.0) specification. The latest specification promises up to a 3,940MB/s transfer rate, which is four times the original spec. As per the previous SD Express specification, the NVMe protocol is used to enable the fastest transfers possible but this time around it can use up to a two-lane PCIe 4.0 connection.
It has been about 18 months since the publication of the SD Express 7.0 spec that introduced the PCIe 3.1 and NVMe architectures to SD memory card design. Leveraging the latest PCIe version 4.0 specification helps take the standard further, doubling the potential transfer rates - and quadrupling the transfer speeds compared to the original SD Express spec.
The extra speed provided by SD8.0 will be particularly appealing in the fields / professions of image and video capture. Activities like taking slow motion videos or burst photos at athletic events could benefit from greater frames/detail in captures. The SDA asserts that "4K and 8K video capture and playback, as well as 360-degree videos can be recorded and played back flawlessly". Additionally, it sees the latest cards becoming useful in video games systems. Perhaps SD8.0 is the tech behind the Microsoft Xbox Series X storage expansion cards.
These new SD Express cards support capacities up to SDUC, which theoretically means up to 128TB in capacity. However cards with such capacity are not likely to be arriving soon, even the SD8.0 spec will take a while to precipitate both cards and readers capable of making the most of this technology.
Card and card reader max achievable transfer speed table.
The SDA says that backwards compatibility is maintained by the advancing standard. Remember, the SD 7.0 specification (SD7.0) was followed up within months by the microSD Express 7.1 specification, so one may expect the SDA to follow the same MO this time around, if you are interested in the smaller form factor memory cards.