Silicon Movement has introduced their first SD Card controller to help the NVMe-based SD Specific interface. The brand new SM2708 controller is able to sequential switch speeds of 1700 MB/s, vastly increased than the 104 MB/s most SD units and playing cards are restricted to utilizing the older however widely-supported UHS-I interface.
In 2018, model 7.0 of the SD specification launched the PCIe and NVMe-based SD Specific interface as the brand new means ahead for SD playing cards. The older UHS-II and UHS-III interfaces developed in variations 4 by way of 6 of the SD commonplace and able to speeds from 156 MB/s to 624 MB/s have been deserted in favor of a single lane of PCIe gen3 (~985 MB/s). Final 12 months, model 8.0 of the SD specification added help for PCIe gen4 speeds and a second PCIe lane, bringing the theoretical most switch velocity as much as virtually 4 GB/s.
Silicon Movement’s SM2708 is a two-lane controller, however nonetheless utilizing PCIe gen3 velocity, therefore the highest velocity cannot fairly attain 2 GB/s. This has the potential to convey SD card efficiency as much as close to the degrees of entry-level shopper NVMe SSDs for laptops and desktops—aggressive with SSDs primarily based on slightly-outdated controllers just like the Phison E8T or Silicon Movement SM2263XT. The SM2708 controller makes use of two NAND channels as a substitute of the 4 usually utilized by entry-level SSD controllers, however the SM2708 is able to a 1200 MT/s IO velocity that permits it to get good efficiency out of current NAND flash generations with out the ability and dimension penalties of a four-channel answer.
In 2019, Silicon Movement’s major competitor Phison introduced their PS5017 SD Specific controller. That is primarily based on the sooner SD 7.0 specification and thus is a PCIe 3 x1 design and restricted to about 870 MB/s. In February 2021 Phison introduced they have been about to begin transport playing cards primarily based on this answer. Silicon Movement’s SM2708 controller won’t take that lengthy to show into precise merchandise, however they clearly have missed out on the primary spherical of SD Specific competitors—although they can leapfrog Phison’s answer.
Underlying all of the developments associated to current flash reminiscence card requirements has been the problem of poor adoption. For years, storage tech has been advancing a lot quicker than digicam tech. Storage expertise corporations stand prepared to provide extra superior reminiscence playing cards, however they can’t succeed out there except there are host units prepared to make use of the upper efficiency. We have seen a decade of failed successors to the previous SD and CF requirements that now appear pitifully gradual. SD’s UHS-II and UHS-III, CF’s CFast and XQD, and UFS playing cards have all been demonstrated as working applied sciences and all ultimately made it to market to some extent, however with very restricted success. The SD and CF worlds have converged on PCIe and NVMe as the way in which ahead, adopting interfaces that have already got a thriving ecosystem and long-term viability in different kind elements. That makes it extra possible that requirements like SD Specific will truly catch on, however it could nonetheless be a number of years earlier than PCIe-based interfaces are supported on any telephones or greater than a handful of high-end cameras.