Switch 2 Needs microSD Express; Steam Deck Takes UHS-I

Switch 2 is the one handheld here whose maker requires a microSD Express card: Nintendo says it takes nothing else, up to 2TB. The original Switch, Steam Deck, ROG Xbox Ally and Ally X all list standard microSD slots (UHS-I or UHS-II), the Ally X20 has an Express reader that also takes UHS-I, and Lenovo states only “up to 2TB” for the Legion Go 2.

Every handheld, by what its maker states

Handheld	Card standard the maker states	Max capacity stated	Does a standard microSD card work?
Nintendo Switch 2	microSD Express only	2TB	No: screenshots and videos only
Nintendo Switch, Switch Lite, Switch OLED	microSD, microSDHC, microSDXC; UHS-I recommended	2TB	Yes
Steam Deck OLED and LCD	UHS-I; supports SD, SDXC, SDHC	Not stated	Yes; the Deck reformats it
ROG Xbox Ally, ROG Xbox Ally X	UHS-II reader; supports SD, SDXC, SDHC	Not stated	Yes
ROG Xbox Ally X20	microSD Express reader; also UHS-I (DDR200 mode)	Not stated	Yes, as UHS-I
Legion Go 2	“microSD card reader”, class not stated	2TB	Lenovo does not say

The wording in the second column is each maker’s own, read on 14 October. Where a cell says “not stated”, the maker’s spec line exists and we read it in full; it just does not give that figure.

Switch 2: Express, and nothing else

Nintendo’s compatibility page is blunt: “Nintendo Switch 2 is only compatible with microSD Express cards.” A card you used in an original Switch “will not allow you to save or load digital games or save data”, though Switch 2 can open the screenshots and videos on it. Nintendo supports Express cards up to 2TB, and says the first one you insert needs a system update over the internet.

Look for the word Express, or the “EX” mark Nintendo highlights on its example card, rather than the capacity. What that adds to the price of the console is in what a console costs after you buy it.

Original Switch: any microSD, and Express adds nothing

The Switch, Switch Lite and Switch OLED take microSD (up to 2GB), microSDHC (4GB to 32GB) and microSDXC (64GB to 2TB). Nintendo recommends a UHS-I card rated 60 to 95 MB/sec, and notes that game save data stays in system memory rather than on the card.

An Express card does work in an original Switch, but Nintendo says it reads and writes there at the speed of an ordinary microSD card. If you are moving from a Switch to a Switch 2, the old card does not carry your games across; an Express card bought for the Switch 2 would work in both.

Steam Deck: UHS-I, formatted by the Deck

Valve’s tech specs for both the OLED and the LCD Steam Deck give the same line: “microSD UHS-I supports SD, SDXC and SDHC”. Valve does not state a maximum capacity or a speed rating. Its FAQ adds that the Deck formats cards to ext4 itself, so anything already on a card from a camera or a Switch is erased when the Deck formats it. Valve also says the Deck can boot from microSD.

More on what the Deck is, and why its storage slot matters, is in what a Steam Deck actually is.

ROG Xbox Ally family: UHS-II, except the X20

Asus lists a UHS-II microSD reader on both the ROG Xbox Ally and the ROG Xbox Ally X, supporting SD, SDXC and SDHC cards. The Ally X20 changes the slot to a microSD Express reader, which Asus says supports “up to SD v8.0, PCIe Gen4 x1; UHS-I with DDR200 mode”. So a standard card still works in the X20, through its UHS-I mode; Asus does not list UHS-II for it.

Asus’s pages for the Xbox Ally and Ally X do not mention Express cards, and none of the three state a maximum capacity. How the three models differ beyond the slot is in which ROG Xbox Ally to buy.

Legion Go 2: 2TB, class unstated

Lenovo’s US page for the Legion Go Gen 2 promises “up to 2TB microSD card expansion”, and its PSREF spec sheet lists a “microSD card reader”. Neither names UHS-I, UHS-II or Express, so Lenovo’s pages do not tell you which cards it reads at full speed. The Go 2’s versions are set out in the Legion Go line-up.

What none of them state

Speed ratings such as A1, A2 and V30 appear on none of the handheld spec pages we read; the only speed figure is Nintendo’s 60–95 MB/sec recommendation for the original Switch. Treat a seller’s claim that a card is “made for Steam Deck” or “for ROG Ally” as the seller’s, not the handheld maker’s.

Questions people ask

Does Switch 2 need a microSD Express card?

Yes. Nintendo says Switch 2 is only compatible with microSD Express cards, up to 2TB. A standard microSD card from an original Switch cannot hold Switch 2 games or save data; Nintendo says you can still load Switch screenshots and videos from it.

Can I use my old Switch microSD card in a Switch 2?

Not for games. Nintendo says a card used on an original Switch will not let a Switch 2 save or load digital games or save data. It can still load the screenshots and videos you captured on it.

What microSD card does the Steam Deck use?

Valve lists a UHS-I slot that supports SD, SDXC and SDHC cards on both the OLED and LCD models. It does not state a maximum capacity. The Deck formats a card to ext4 itself, so back up anything already on it first.

Does the ROG Xbox Ally take microSD Express?

Only the X20, which Asus lists with a microSD Express reader that also supports UHS-I. The ROG Xbox Ally and Ally X have UHS-II readers supporting SD, SDXC and SDHC, and Asus does not say they take Express cards.

What is the biggest microSD card the Legion Go 2 takes?

Lenovo states up to 2TB of microSD expansion on its Legion Go Gen 2 page. Its PSREF spec sheet lists a “microSD card reader” without naming UHS-I, UHS-II or Express.

Does a microSD Express card work in an original Switch?

Yes, Nintendo marks it compatible, but on an original Switch it reads and writes at the speed of a standard microSD card. Buying Express for an original Switch alone gains nothing Nintendo describes.