The Asus ROG Ally handheld PC is launching with speed, and I’m not just talking about its fast processor that sets it apart from the Steam Deck and other competitors. The ROG Ally’s UHS-II microSD card interface allows for faster reading and writing speeds than UHS-I, the baseline spec found in the Steam Deck, the Nintendo Switch, and in several other devices. In other words, you’ll likely see much faster download speeds.
According to Lexar, UHS-II triples the maximum transfer speed of UHS-I, topping out at 312 MB/s instead of 104 MB/s. However, compared to the proliferation of slower microSD cards, there are very few UHS-II microSD cards out there. Currently, household names in storage like Samsung and SanDisk do not make UHS-II microSD cards. So far, it’s just Lexar, Adata, and some brands that, frankly, I’ve never heard of.
The few options that exist are much more expensive than what you might be used to paying for a microSD card. What’s a little more concerning is that the current options don’t run at the full speed allowed by the UHS-II interface. We’ll get there one day, I’m sure. However, there’s some good news, which is that UHS-II microSD cards are backwards compatible with UHS-I gadgets, such as the Steam Deck, although you’ll see slower transfer speeds than what you paid the big bucks for.
We’ll keep this list updated as newer microSD card models release.