SD 9.1 Specifications: Doubling Speed of MicroSD Memory Cards to 2GB/s

In late October, the SD Association published new specifications SD 9.1which doubles the speed of microSD memory cards to 2 GB/s (or more precisely 1969 MB/s).

This is about the same as modern SSDs, with which they have a lot in common. The new memory sticks also run internally on the PCIe 4.0 bus and use the NVMe communication protocol. It’s just that they’re still cards that fit under your fingernail.

Old cards that you may still have in your drawer at home, using the High Speed interface with a speed of up to 25 MB/s. Then came the next generations using wider buses UHS-I, UHS-II and UHS-III, which moved the speeds to 104, 312 and 624 MB/s. It wasn’t until the SD 7.0 standard from 2018 that the Express interface came with a single PCIe 3.0 lane and a speed of 985 MB/s. Two years later, SD 8.0 arrived, pushing the possibilities to 3938 MB/s thanks to PCIe 4.0 and a second lane, but this requires a large SD card with a third line of contacts.

Eternal waiting

But the arrival of new cards is slow. There are practically no models for the UHS-III interface available on the market either. Several large SD Express with speeds of up to 1 GB/s only came after 2021, but you still won’t find them in the small microSD format. So the wait for twice as fast microSD will continue for a few more years.

They are not even readers. Cell phones are slowly phasing out cards. In (mirrorless) cameras, you can usually find only SD with UHS-II interface, and if there is a hunger for higher speeds somewhere, the more affordable fast CFexpress cards are used. Memory sticks reaching up to 2 GB/s would also need Thunderbolt 3/4/5, USB4 or USB 3.2 Gen 2×2 in the case of external readers, which is still quite exotic.

Anyway, the SD Association has already prepared more logos for future cards, as if there weren’t enough already. We will meet the brands E150, E300, E450 and E600, while the number indicates the minimum sequential read and write speeds.