New SD card specification promises up to 4 GB per second transfer
The SD Association announced the SD 8.0 Specification for SD Express memory cards receives even faster transfer speeds by using the PCI Express (PCI) 4.0 specification delivering a maximum of nearly 4 gigabytes per second (GB/s) data transfer rate. These full-sized cards continue to use the NVMe Express (NVMe) upper layer protocol enabling advanced memory access mechanism. SD Express memory cards using SD 8.0 specification maintain backward compatibility.
“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,” said Mats Larsson, senior market analyst, Futuresource. “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 Express gigabyte speeds bring new storage opportunities for devices with demanding performance levels, across a variety of industries. The cards can move large amounts of data generated by data-intense wireless or wired communication, super-slow-motion video, RAW continuous burst mode and 8K video capture and playback, 360-degree cameras/videos, speed-hungry applications running on cards and mobile computing devices, ever-evolving gaming systems, multi-channel IoT devices and automotive to name a few. SD Express will be offered on SDHC, SDXC and SDUC memory cards.
“By dramatically increasing the speeds for SD Express we’re giving device manufacturers and system developers more storage choices,” said Hiroyuki Sakamoto, SDA president. “SD 8.0 may open even more opportunities for extra high-performance solutions using removable memory cards.”
SD Express uses the well-known PCIe 4.0 specification and the latest NVMe specification (up to version 1.4) defined by PCI-SIG and NVM Express, respectively. SD 8.0 specification provides two transfer speed options for SD Express memory cards. The two transfer speeds are accomplished by supporting either PCIe 3.0 x2 or PCIe 4.0 x1 architectures with up to ~2GB/s and with PCIe 4.0 x2 technology with up to 4GB/s. SD Express cards offering PCIe 4.0 x1 architecture use the same form factor as defined for SD 7.0 specification cards with the second row of pins to deliver transfer speeds up to 2 GB/s. SD Express cards supporting dual PCIe lanes (PCIe 3.0 x2 or PCIe 4.0 x2 technologies) have three rows of pins.
The SDA makes adoption of SD Express easy allowing companies to use existing test equipment and saving in product development costs. The SD 8.0 specification continues giving system developers access to PCIe and NVMe technologies, such as Bus Mastering, Multi Queue (without locking mechanism) and Host Memory Buffer.
Two revised white papers, “SD Express Cards with PCIe and NVMe Interfaces,” and “SD Express and microSD Express Memory Cards: The Best Choice for Your Future Product Designs” provide an in-depth look at the opportunities created by SD Express. More information is available on our website.