Best microSD Cards for Steam Deck, ROG Ally, and ROG Xbox Ally (2026)
Steam Deck OLED. Photo: SparklesTrainNerd, CC BY-SA 4.0.
microSD picks by handheld
The right card depends on which slot the handheld has, and the three main options here each use a different one.
- Steam Deck (LCD and OLED): a UHS-I slot. The SanDisk Extreme 1TB is the one to buy, and the Samsung EVO Select 512GB is the cheaper option.
- ROG Ally (2023), ROG Ally X (2024), ROG Xbox Ally, and ROG Xbox Ally X: a UHS-II slot. A UHS-II card like the ProGrade Digital V60 Gold 512GB runs fastest, and the SanDisk Extreme is the better value at 1 TB.
- ROG Xbox Ally X20: a microSD Express slot. The Samsung P9 Express 512GB is the pick, and it was cheaper than most of the regular cards in this guide on Amazon on October 23.
Every card here is a full-size 512 GB or 1 TB card except the Lexar, because a 256 GB card fills up after a handful of modern games.
Which slot your handheld has
Valve's Steam Deck tech specs list a UHS-I microSD slot that supports SD, SDXC, and SDHC cards. The UHS-I bus tops out at 104 MB/s, so any decent card hits the same ceiling in a Steam Deck, and capacity, price, and warranty matter more than the speed on the box.
ASUS's guide to installing games on an SD card, updated October 13, 2026, says the ROG Ally (2023), ROG Ally X (2024), ROG Xbox Ally, and ROG Xbox Ally X "all feature a UHS-II microSD card slot." UHS-II cards have a second row of contacts and are rated for roughly 250 to 300 MB/s reads. A regular UHS-I card still works in these models, at UHS-I speed.
The ROG Xbox Ally X20 replaces that slot with a microSD Express reader, which connects over PCIe like a small SSD. ASUS's product page says the reader is "fully backward compatible with standard microSD cards (including UHS-I)" and that "UHS-II cards will run at UHS-I speeds." Anyone moving a UHS-II card from an older Ally to an X20 keeps their games but loses the extra speed.
ROG Xbox Ally X on display. Photo: Kyu3a, CC BY-SA 4.0.
Quick comparison
| Card | Capacity | Bus | Rated read | Best slot for it | Warranty |
|---|---|---|---|---|---|
| SanDisk Extreme (SDSQXH9-1T00) | 1 TB | UHS-I | Up to 245 MB/s | Steam Deck, any ROG Ally | Not stated on the listing |
| Samsung EVO Select | 512 GB | UHS-I | Up to 160 MB/s | Steam Deck | 10 years limited |
| Samsung PRO Plus | 1 TB | UHS-I | Up to 180 MB/s | Steam Deck, any ROG Ally | Not stated on the listing |
| ProGrade Digital V60 Gold | 512 GB | UHS-II | Up to 250 MB/s | ROG Ally, Ally X, Xbox Ally, Xbox Ally X | 3 years |
| Lexar Professional GOLD | 256 GB | UHS-II | Up to 280 MB/s | ROG Ally, Ally X, Xbox Ally, Xbox Ally X | 10 years limited |
| Samsung P9 Express | 512 GB | microSD Express | Up to 800 MB/s | ROG Xbox Ally X20 | 3 years limited |
| SanDisk microSD Express | 512 GB | microSD Express | Up to 880 MB/s | ROG Xbox Ally X20 | Not stated on the listing |
These are the makers' sequential read ratings, which a card only reaches in a slot that supports its bus. Every UHS-I card here runs at about 100 MB/s in a Steam Deck.
Best for Steam Deck: SanDisk Extreme 1TB
Check the SanDisk Extreme 1TB price on AmazonThe current SanDisk Extreme 1TB (model SDSQXH9-1T00-GZ6MA) is rated at up to 245 MB/s read and 170 MB/s write, according to its Amazon listing. A Steam Deck can't use most of that speed, but 1 TB holds a large library.
The same card is also a good fit for any ROG Ally when a 1 TB UHS-II card costs too much. It runs at UHS-I speed there, slower than a UHS-II card but with twice the room for the money.
It is also on eBay. Counterfeit SanDisk cards are common on marketplaces, so buy from a seller with a return policy and check the capacity with a tool like H2testw or F3 when the card arrives.
Cheaper Steam Deck card: Samsung EVO Select 512GB
Check the Samsung EVO Select 512GB price on AmazonThe Samsung EVO Select 512GB is Samsung's Amazon-only version of the EVO Plus, rated at up to 160 MB/s read. In a Steam Deck's UHS-I slot it runs at about the same speed as the pricier cards here, so it is the one to get when 512 GB is enough. Samsung backs it with a 10-year limited warranty. It was $133.99 on Amazon on October 23, about half the price of the 1 TB SanDisk.
Steam Deck OLED owners with the 512 GB model can add this card for 1 TB in total, which covers most libraries.
Alternative 1TB card: Samsung PRO Plus 1TB
Check the Samsung PRO Plus 1TB price on AmazonThe Samsung PRO Plus 1TB is rated at up to 180 MB/s read. In a Steam Deck it performs about the same as the SanDisk Extreme, so buy whichever 1 TB card is cheaper on the day. On October 23 that was the SanDisk, at $259.69 to the Samsung's $325.95, and the Samsung listing was sold by a third-party seller rather than Amazon.
Best for ROG Ally and ROG Xbox Ally: ProGrade Digital V60 Gold 512GB
Check the ProGrade Digital V60 Gold 512GB price on AmazonThe ProGrade Digital microSDXC UHS-II V60 Gold comes in 512 GB, a size few UHS-II microSD cards are sold in, and ProGrade rates it at up to 250 MB/s read and 130 MB/s write, with a 3-year warranty. In a ROG Ally, Ally X, Xbox Ally, or Xbox Ally X, that is well above the 104 MB/s ceiling of a standard UHS-I bus, which shortens game installs and load screens for games stored on the card.
UHS-II cards cost much more per gigabyte. This card was $342.89 on Amazon on October 23, more than the 1 TB SanDisk Extreme. ASUS's guide says read speed matters most for load times, and that V60 and V90 ratings mainly matter for recording video. Buy the ProGrade for speed or the SanDisk Extreme for capacity.
Smaller UHS-II card: Lexar Professional GOLD 256GB
Check the Lexar GOLD 256GB price on AmazonThe Lexar Professional GOLD microSD is rated at up to 280 MB/s read and 180 MB/s write, is UHS-II, V60, and A1, and has a 10-year limited warranty. The largest size on Amazon is 256 GB, which suits a ROG Ally owner who keeps a few favorite games on the card and the rest on the internal SSD. For a bigger library, the ProGrade or the SanDisk Extreme is the better buy.
Best for ROG Xbox Ally X20: Samsung P9 Express 512GB
Check the Samsung P9 Express 512GB price on AmazonThe Samsung P9 Express is a microSD Express card rated at up to 800 MB/s read, with a 3-year limited warranty. Amazon lists it for the Nintendo Switch 2, but microSD Express is a standard, so the same card works in the X20's reader. Its 800 MB/s rating is about three times that of the fastest UHS-II card here.
It was also the cheapest card in this guide on October 23, at $99.97 for 512 GB. A microSD Express card works in a UHS-I slot too, but Samsung rates the P9 at about 90 MB/s there, a little slower than a regular UHS-I card in a Steam Deck.
Alternative X20 card: SanDisk microSD Express 512GB
Check the SanDisk microSD Express 512GB price on AmazonSanDisk rates its microSD Express cards at up to 880 MB/s read, a little above the Samsung, and its listing says the card runs at UHS-I speed in UHS-I and UHS-II slots. The 512 GB card was $129.99 on Amazon on October 23. Buy it if it is cheaper than the P9 Express on the day, or step up to the Lexar PLAY PRO 1TB for more room. The Switch 2 microSD Express guide covers these cards in more detail.
Setting up the card
Steam Deck: insert the card, open Settings, choose System, and select Format next to Format SD Card. Formatting erases the card and can take several minutes. SteamOS formats it as ext4, and the card can then be set as the default install location under Settings, then Storage. A card formatted on a Steam Deck can't be read by Windows without extra software.
ROG Ally family: Windows sees the card as a normal drive. ASUS's guide walks through adding it as a library folder in Steam, the Xbox app, and other launchers. Format it as NTFS or exFAT on the handheld itself before installing games.
Why cards cost more this year
Memory prices rose sharply in 2026. Meta and Valve both blamed memory and storage costs when they raised prices on the Quest 3S and Steam Deck OLED this year. The prices quoted above were on Amazon on October 23 and will change, so check the current price before ordering. Black Friday is November 27 and is a good time to buy a large card.
Steam Deck and ROG Ally microSD FAQ
Does a UHS-II card work in a Steam Deck?
Yes. It runs at UHS-I speed in the Deck, so there is no reason to pay extra for one.
Does a microSD Express card work in a Steam Deck or older ROG Ally?
Yes, at UHS-I speed. Samsung rates the P9 Express at about 90 MB/s in a UHS-I slot.
What is the biggest card the Steam Deck takes?
Valve's spec page lists SDXC support, which covers cards up to 2 TB. 1 TB is the most practical size because 2 TB cards cost far more.
Should I upgrade the internal SSD instead?
Both the Steam Deck and the ROG Ally family take an internal M.2 SSD, which is faster than any microSD card. The Steam Deck takes an M.2 2230 drive, and the ROG Xbox Ally models use a 2280 drive. Swapping it means opening the case and reinstalling the operating system, so a microSD card is the easier upgrade for most people.
Can I move a card between a Steam Deck and a ROG Ally?
Not without reformatting. The Steam Deck uses ext4 and Windows handhelds use NTFS or exFAT, so the games have to be reinstalled.
Final verdict
For a Steam Deck, get the SanDisk Extreme 1TB, or the Samsung EVO Select 512GB to save money, since the Deck's UHS-I slot evens out the speed differences. For a ROG Ally, Ally X, Xbox Ally, or Xbox Ally X, the ProGrade V60 Gold 512GB gives UHS-II speed, and the SanDisk Extreme 1TB gives more room for less money. For a ROG Xbox Ally X20, get the Samsung P9 Express 512GB, which was the cheapest and fastest card in this guide on October 23.
Where to buy
Where to buy
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