The SD Association has announced the eighth revision to the SD Express specification — bringing the maximum possible throughput from a compatible SD card to just shy of 4GB/s.
For many embedded systems, high-speed storage means something based on SATA, USB 3.0, or a classic Non-Volatile Memory Express (NVMe) SSD connected to an M.2 slot. SD Express memory cards, however, are becoming increasingly performant — and in their latest SD Express form can deliver just short of 4GB/s sustained throughput.
“By dramatically increasing the speeds for SD Express we're giving device manufacturers and system developers more storage choices," explains Hiroyuki Sakamoto, president of the SD Association. “SD 8.0 may open even more opportunities for extra high performance solutions using removable memory cards."
That extra burst of speed comes courtesy of two technologies: Non-Volatile Memory Express (NVMe), the same standard that drives high-speed M.2 SSDs, and PCI Express 4.0. Built into full-size and backwards-compatible SD Card form factors, these are accessible only on devices adopting the latest SD 8.0 standard — but will fall back to slower, older access methods if inserted into older devices.
"SD Express' use of even faster PCIe and NVMe architectures to deliver faster transfer speeds creates more opportunities for devices to use SD memory cards," opines Mats Larsson, senior market analyst at Futuresource, of the upgrade. "This combination of trusted and well-known technologies makes it easier for future product designs to leverage the benefits of removable storage in new ways."
SD Association members are now able to download the latest standard from the official website; thus far, none have come forward to suggest when the first SD 8.0 certified products will reach market.