DISCLAIMER: Switchroot is neither affiliated nor associated with any SD card manufacturer, and our reviews are our opinions based on benchmarks, average binning, and other data we have collected.
ddr200is essentially the SD version of the eMMC HS400 standard, created by SanDisk. However, their reference implementation required a DLL mechanism that is not supported on the Switch's reader. Every other vendor that supports the standard aligns transfers on clock edge instead of whenever based on the DLL mechanism, allowing
ddr200to work on these cards as a version of SDR104 (normally the fastest speed spec for this reader) that samples on rising and falling edge. See the comment in this commit from CTCaer for details.
Samsung makes the best UHS-I microSD cards money can buy. The ProPlus line (dark blue, 2022-2023) and ProUltimate (nearly black, 2023) are the fastest we've ever seen. These cards are compatible the the
ddr200 specification as implemented in
hekate and the L4T kernel. This goes beyond the 104 MB/s max of standard SDR104 and allows for the best performance possible on Switchroot operating systems. The lower tier Evo and older Pro models still work very well, but some firmware bugs have been reported and they are not as fast.
Silicon Power is a Taishin brand with an awful website and sketchy listings...but if you get one direct from a verified retailer, you are in luck. Not quite as fast or reliable as the Samsung cards, Silicon Power ranks in as a budget option for high speed and high capacity cards. There are many tiers of the SP cards, and not all have been tested, but the Superior branding is their recommendation for game storage--likely the best option.
SanDisk is the brand most people think of when they think of an SD card given their wide availability, decent prices, and high market share--but they come with many caveats. The first issue is lifespan--SanDisk cards will degrade quickly over time, and this can even lead to eventual write-locks and other failures. Another big caveat with SanDisk cards is their lack of proper
ddr200 support...despite being the vendor that produced the specification originally. See the comment in this commit for details. One last big SanDisk issue is branding--given their lack of year-specific branding and many SKUs, it can be hard to find a good SanDisk card. Our advice is to check for a recent listing (maybe check model number if available) and use only SanDisk Extreme cards as the Ultras and everything below are basically useless for Switchroot. Our real advice is to just buy a Samsung card and move on with life.
Micron is a silicon manufacturer that sells some products, like microSD cards, directly. They produce industrial-grade cards generally meant for production devices. Likely their high cost would be less of an issue in bulk. They do sell cards in sizes of unrivald proportion (like the 1.5TB card) but they are prohibitively expensive, so should only be bought with that purpose in mind. That being said, they do seem to be fast, reliable cards from a reputable manufacturer.
More to come! The above is the most relevant, but we will add "reviews" for other vendors and newer models in the future.