According to the pic linked from this article <https://www.theregister.co.uk/2020/05/20/sd_8_for_sd_express/>, the new SD card spec uses PCIe instead of the previous “SD Bus” interface to achieve around ... is it 4GB/s, or 4Gb/s? The article says it both ways, while the diagram uses capital B throughout. The current fastest SD cards have two rows of pins; this spec adds a third row.