The Asus ROG Ally really shines when placed side by side with the Steam Deck and a host of other handheld devices. Its latest iteration, the ROG Ally X released in 2024, takes things up a notch with considerably better performance, a more impressive screen, and improvements in how it feels to hold and use. One standout feature across the ROG Ally line is the inclusion of a UHS-II microSD card slot. This is a significant upgrade, offering faster reading and writing speeds compared to the UHS-I slots found on the Steam Deck, Nintendo Switch, and many other devices. What this means for you is potential quicker download speeds, provided you have the right card.
Lexar tells us that UHS-II can transfer data three times quicker than UHS-I, reaching speeds up to 312 MB/s compared to the 104 MB/s max of UHS-I. But here’s the catch—despite the wide availability of microSD cards, UHS-II options are scarce. Big names in storage like Samsung and SanDisk don’t make them. The few UHS-II cards available come with a heftier price tag than you might expect for a typical microSD card. Additionally, the current selection doesn’t even hit the maximum speeds that the UHS-II standard can theoretically provide.
If you’re handy enough to pop open your ROG Ally (don’t worry, it won’t affect your warranty), you might want to look at upgrading with an M.2 SSD. Not only does this offer better value per gigabyte, but it can also deliver performance that outpaces what you’d get with a microSD card. For those who prefer to keep things simple and don’t mind spending a bit more for marginally increased speed, there are a few options available that we’ve noted below.
On the other hand, if your main goal is just to expand your storage without needing blistering speeds, you’ve got a plethora of choices from brands like SanDisk, Samsung, and Lexar. These options can provide up to 1.5TB of additional space for your device, which should be more than enough for most users.
