The MicroSD 3.0 card has a 9-pin interface, designed to operate at a maximum frequency of 208MHz. It can alternate communication protocol between the SD mode and SPI mode. It performs data error detection and correction with very low power consumption.

SD 4.0 Cards use the UHS-II bus interface, which features two rows of pins rather than the single row found in UHS-I. The original single row of pins is compatible with the preset, high-speed, and UHS-I transmission modes.

The "SD7. 0 Specification" increases the maximum capacity of SD cards to 128TB. Theoretically, the maximum transfer speed can reach 985mb/s. Therefore, SD 7.0 can be applied to the design of tablet, monocular, digital camera, drone, vehicle 3C, … etc.

SD Express 8.0 represents the bleeding edge of high-speed non-volatile memory. Like CFexpress cards and the M.2 NVMe SSDs you see in many computers these days, SD Express 8.0 is a form of PCIe NVMe storage. In this case, the new spec is taking advantage of the PCIe 4.0 standard to reach speeds of almost 2GB/s per lane, with the fastest cards giving you two lanes to work with.