SD Association Unveils SD 8.0 Spec for SD Express Memory Cards With 4GB/s Transfer Rate with PCIe 4.0

The SD Association (SDA) announced the SD 8.0 spec for SD Express memory cards receives faster transfer speeds by using the PCIe 4.0 spec delivering a maximum of nearly 4GB/s data transfer rate.

SD Express memory card examples

These full sized cards continue to use the NVMe upper layer protocol enabling advanced memory access mechanism. SD Express memory cards using SD 8.0 spec 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°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.

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“By dramatically increasing the speeds for SD Express we’re giving device manufacturers and system developers more storage choices,” said Hiroyuki Sakamoto, president, SDA. “SD 8.0 may open even more opportunities for extra high performance solutions using removable memory cards.“

“PCI-SIG is pleased to see that SDA is continuing to adopt even faster PCIe technology configurations using PCIe 4.0 interface and dual lanes for one of the top leading removable memory cards – SD,” said Al Yanes, president and chairman, PCI-SIG. “PCIe spec conformance tests are available today by major test vendors, offering a significant advantage for any new PCIe technology adopter.“

“NVMe is the industry-recognized performance SSD interface from the client to the datacenter, shipping in millions of units,” said Amber Huffman, president, NVM Express, Inc. “Consumers will benefit by SD Association continuing the adoption of the NVMe base spec for their latest SD Express cards.“

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SD Express uses the PCIe 4.0 spec and the NVMe spec up to version 1.4 defined by PCI-SIG and NVMe, respectively. SD 8.0 spec provides 2 transfer speed options for SD Express memory card. The 2 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 spec cards with a second row of pins to deliver transfer speeds up to 2GB/s. SD Express cards supporting dual PCIe lanes (PCIe 3.0 x2 or PCIe 4.0 x2 technologies) have 3 rows of pins.

Pin layouts of SD Express memory cards using single or dual lane technology

The SDA makes adoption of SD Express allowing companies to use existing test equipment and saving in product development costs. The SD 8.0 spec continues giving system developers access to PCIe and NVMe technologies, such as Bus Mastering, Multi Queue (without locking mechanism) and host memory buffer.