SD cards are getting a makeover and thanks to the presence of a new connector ensure very high maximum speeds. Here are the features
If the SD Card standard has survived for over two decades (in fact, the first version dates back to August 1999) it is because it has been constantly developed and improved to make external memory cards ever larger and ever faster. And the development hasn't stopped at all: the SD Association has just presented its latest evolution, version 8.0.
With this version, the transfer speed increases incredibly: from 985 MBps of the current SD Express cards to 3,940 MBps of the 8.0 ones. That's practically 4 gigs per second, four times the previous limit and about five times faster than the fastest cards currently on the market, the 624 MBps UHS-III. The speed increase was made possible by a new design of the electrical connections on the back of the card, but the new SD Card 8.0 will be backwards compatible and can be read and written, albeit at lower speed, by all current readers integrated into digital cameras, laptops, smartphones, tablets.
SD Card 8.0: the new design
The big news in the design of the next generation SD memory cards is actually almost invisible: two small additional areas reserved for new connection pins. These pins will be used for the PCIe connection, the real technical innovation of version 8.0. If the card reader will be compatible with the PCIe 3 standard then the speed will be up to 1,920 MBps, if it will be compatible with PCIe 4 it will reach the maximum speed of 3,940 MBps. The readers currently on the market, however, are not connected to the devices that host them via PCIe, so they will not be able to exploit these cards at maximum speed. In these cases, then, the next-generation SD cards will be read and written to via the pins already present in the previous standards, which also remain on the new cards to ensure maximum backward compatibility.
What's the point of 4 GBps
These new, ultra-fast SD Express memory cards will hit the market in late 2020 and early 2021, with Samsung and Sony likely to be the first manufacturers to make and sell them. Their main destination will be, at least initially, the 8K resolution professional camcorder market, which needs very high transfer rates to store all captured frames without loss. A speed of 4 GBps, for example, opens the door to shooting at very high frame rates in 8K (provided that the rest of the electronics can handle such demanding data streams). Next will come the first top-of-the-line smartphones with the SD Card slot in version 8.0. And this could open the door to new choices by manufacturers: for example, integrating little memory in the less expensive versions of the latest generation of smartphones, then leaving the possibility for users to expand it without risking that the additional memory will be too slow and penalize the performance of the device.