Filed under: News, SD Express

Silicon Motion Announces SM2708 SD Express Controller

Silicon Movement has introduced their 1st SD Card controller to guidance the NVMe-dependent SD Specific interface. The new SM2708 controller is able of sequential transfer speeds of 1700 MB/s, vastly increased than the 104 MB/s most SD equipment and playing cards are minimal to using the older but extensively-supported UHS-I interface.

In 2018, variation seven. of the SD specification introduced the PCIe and NVMe-primarily based SD Express interface as the new way forward for SD cards. The older UHS-II and UHS-III interfaces created in versions 4 through six of the SD typical and able of speeds from 156 MB/s to 624 MB/s ended up abandoned in favor of a one lane of PCIe gen3 (~985 MB/s). Last yr, edition 8. of the SD specification added help for PCIe gen4 speeds and a 2nd PCIe lane, bringing the theoretical optimum transfer speed up to pretty much four GB/s.

Silicon Motion’s SM2708 is a two-lane controller, but nevertheless working with PCIe gen3 speed, hence the best velocity can not really achieve two GB/s. This has the potential to carry SD card effectiveness up to close to the concentrations of entry-stage buyer NVMe SSDs for laptops and desktops—competitive with SSDs based mostly on a little-outdated controllers like the Phison E8T or Silicon Motion SM2263XT. The SM2708 controller utilizes two NAND channels in its place of the four ordinarily made use of by entry-level SSD controllers, but the SM2708 is able of a 1200 MT/s IO pace that enables it to get great general performance out of new NAND flash generations without having the electrical power and sizing penalties of a 4-channel remedy.

In 2019, Silicon Motion’s main competitor Phison introduced their PS5017 SD Express controller. This is based on the before SD 7. specification and therefore is a PCIe three x1 design and style and limited to about 870 MB/s. In February 2021 Phison announced they have been about to commence delivery playing cards based mostly on this option. Silicon Motion’s SM2708 controller may possibly not get that extensive to switch into precise goods, but they obviously have missed out on the 1st spherical of SD Convey competition—though they may well be equipped to leapfrog Phison’s solution.

Fundamental all the developments linked to recent flash memory card benchmarks has been the obstacle of very poor adoption. For decades, storage tech has been advancing much a lot quicker than camera tech. Storage technological know-how companies stand completely ready to provide additional sophisticated memory playing cards, but they are not able to succeed in the market place until there are host units ready to use the larger functionality. We have witnessed a 10 years of unsuccessful successors to the aged SD and CF criteria that now look pitifully sluggish. SD’s UHS-II and UHS-III, CF’s CFast and XQD, and UFS cards have all been shown as doing work technologies and all inevitably made it to marketplace to some extent, but with incredibly restricted achievement. The SD and CF worlds have converged on PCIe and NVMe as the way ahead, adopting interfaces that previously have a flourishing ecosystem and long-phrase viability in other variety aspects. That will make it more possible that criteria like SD Express will essentially catch on, but it could still be several many years prior to PCIe-centered interfaces are supported on any telephones or additional than a handful of substantial-finish cameras.