Valve's Steam Frame headset ships in just two storage sizes — 256GB and 1TB — and VR-ready game libraries fill the smaller one fast. The good news: the Frame has a microSD slot, and it's the easiest storage upgrade in the whole SteamOS family, because a card you load on a Steam Deck or Steam Machine drops straight into the Frame and its games show up ready to play. All three picks here are proven UHS-I cards sized for a real library: the SanDisk Extreme is our best overall, the Samsung PRO Plus is the best value, and the Lexar Play 1TB is the pick when you want the whole backlog with you.
One thing decides almost everything about this choice, and it's easy to get wrong: the Steam Frame's card reader is UHS-I — the same class Valve uses in the Steam Deck and Steam Machine. In the real world that tops out around 100 MB/s no matter what the card is rated for. So the expensive new microSD Express cards (rated 800–900 MB/s) are wasted money here — the slot can't use that speed, and they fall back to UHS-I.
Valve's own engineers say they tested SD storage extensively and that cards "actually work really well" for this job, so buy a good UHS-I card and spend the difference on capacity. If you also own a Steam Machine, the same logic (and the same cards) apply there — see our best microSD cards for the Steam Machine guide — and the rest of the Frame kit is in our best Steam Frame accessories roundup.
Who this comparison is for#
- Anyone picking up the 256GB Steam Frame who wants room for a real VR and flatscreen library without paying the 1TB premium up front.
- Steam Deck and Steam Machine owners who want one card that carries their installed games across every SteamOS device they own.
- People who'd rather spend on capacity than on peak speed the UHS-I slot can't actually deliver.
How we picked#
- UHS-I, not Express. The Frame's slot is UHS-I, so every pick is a top UHS-I card. We deliberately skipped microSD Express cards — the reader can't use their speed, so they're a waste here.
- A2 for load times. With sequential speed capped by the slot, the rating that still matters is A2 (random read/write). A2 cards handle a game's many small file reads better, so levels and menus load quicker. All three are A2, U3, V30.
- Capacity that fits a modern library. Games are large — and a headset you carry around is exactly where you want your library with you — so we weighted usable space heavily and picked cards that scale to 512GB and 1TB.
- Proven in the SteamOS family. Every card here has a long track record in the Steam Deck and Switch — known controllers, real endurance, no anonymous cards. And to be clear about what a card does: it stores and runs games, but the internal storage will always load fastest. A card is the convenience-and-capacity option, not the speed option.
Product 1 — SanDisk Extreme microSDXC (Best Overall)#
The SanDisk Extreme is the card most Steam Deck owners already trust, and that track record is exactly why it's the safe pick for the Frame. It's A2-rated with strong random performance, so games with lots of small assets load about as fast as a UHS-I slot allows, and its sustained write speed comfortably handles dropping a big game onto the card. You're buying a known quantity: mature controller, consistent real-world results, and a long history in exactly this kind of SteamOS use.
It's also built for a device that travels — a headset gets carried, packed and shared more than any console, and the Extreme is shockproof, temperature-proof, waterproof and X-ray-proof, and ships with SanDisk's RescuePro file-recovery software. At 512GB it holds a serious stack of installs, and the same card slots straight into a Steam Deck or Steam Machine, so your library follows you across the whole family. This is the card to buy if you don't want to think about it.
Key specs#
Interface : microSDXC, UHS-I (U3)
Speed class : A2, U3, V30, Class 10
Rated read : Up to ~190 MB/s (slot-limited to UHS-I in the Frame)
Durability : Shock, temperature, water and X-ray proof
Capacities : 256GB / 512GB / 1TB
Warranty : Limited lifetime
Best for : Anyone who wants the proven, no-second-guessing card
Bottom line. The default SteamOS card for a reason — strong A2 random speed, tough build, and a long track record. The safe best-overall choice for the Frame.
Product 2 — Samsung PRO Plus microSDXC (Best Value)#
The Samsung PRO Plus is the card to buy when you want almost everything the Extreme offers for less. It's A2, U3 and V30, matches the important random-read behavior that drives load times, and Samsung's cards are known for running cool and staying reliable over years of use — a nice quality in a card that lives inside a sealed headset and gets written to a lot. For the money, it's hard to beat as an everyday Steam Frame card.
Samsung backs it with the same six-proof protection (water, temperature, X-ray, magnet, drop and wear-out) and a long warranty, so it's every bit as travel-safe as the Extreme. At 512GB it's the sweet spot: enough space to double the 256GB Frame's total storage several times over without paying the 1TB card premium. If you want the best balance of price, durability and speed, this is the one.
Key specs#
Interface : microSDXC, UHS-I (U3)
Speed class : A2, U3, V30, Class 10
Rated read : Up to 180 MB/s (slot-limited to UHS-I in the Frame)
Durability : Six-proof; 10-year limited warranty
Capacities : 128GB / 256GB / 512GB
Best for : The best all-round value for most players
Bottom line. Nearly all of the Extreme's strengths — cool, durable, A2-fast — at a friendlier price. The smart value pick.
Product 3 — Lexar Play 1TB microSDXC (Best Big Capacity)#
If you bought the 256GB Frame and your problem is simply "not enough room," the Lexar Play 1TB solves it in one move — it takes the smaller Frame past the built-in storage of the 1TB model for far less than the price gap between the two headsets. It was built for exactly this job — expanding storage on handheld consoles.
A full terabyte is enough to keep a large library installed and ready without constantly uninstalling to make space. It's A2, U3 and V30, so it behaves like the others in day-to-day loading; the difference you're paying for is capacity, not speed.
Because the slot is UHS-I, the Play loads games at the same real-world pace as the smaller cards here — buying 1TB is about never running out of space, not going faster. That's the honest trade: you pay more per game stored, but you stop managing installs. If you have a big backlog and want all of it in the headset (and portable to a Deck or Machine), this is the card.
Key specs#
Interface : microSDXC, UHS-I (U3)
Speed class : A2, U3, V30, Class 10
Rated read : Up to 160 MB/s (slot-limited to UHS-I in the Frame)
Marketed for : Handheld consoles and gaming devices
Capacities : 256GB / 512GB / 1TB
Best for : Keeping a large library installed at all times
Bottom line. The most space here, purpose-built for handheld gaming. Buy it for the 1TB, knowing the speed matches the cheaper cards.
Which one should you buy?#
For most people, buy the SanDisk Extreme 512GB. It's the proven SteamOS default — strong A2 random speed, tough build, and years of reliable use in exactly this role. It's the card you never think about again.
If you want the same everyday experience for less, buy the Samsung PRO Plus 512GB. It matches the Extreme where it counts, runs cool, and is usually the better deal — the best value for a Steam Frame.
If you bought the 256GB Frame and want the storage question answered permanently, buy the Lexar Play 1TB. Just go in knowing you're paying for capacity, not speed — every card here loads at the same UHS-I pace.
Whichever you pick, skip microSD Express cards — the slot can't use their speed. And if the Frame is joining a Steam Machine or Deck in your setup, one card can serve them all: SteamOS shares card libraries across devices, which is exactly why a good card is the single best-value purchase in the ecosystem. Round out the rest of the kit in our best Steam Frame accessories guide.
FAQ#
Does the Steam Frame support fast microSD Express cards?#
No — its card reader is UHS-I, the same class as the Steam Deck's and Steam Machine's. A microSD Express card will physically work but drops to UHS-I speed, so you'd be paying for performance the slot can't use. A good UHS-I card (like the three here) is the right buy; put the money you save toward more capacity.
Can I move a card between my Steam Deck, Steam Machine and Steam Frame?#
Yes — this is the headline feature. SteamOS shares card libraries, so a microSD card you've set up on any of the three drops into the others and its installed games show up immediately. Valve engineers have confirmed that any card formatted for SteamOS is recognized straight away across the Machine and the Frame. One card can carry your library through the whole family.
Should I buy the 256GB Frame and a big card instead of the 1TB Frame?#
That's the math worth doing. A 512GB or 1TB card costs far less than the price gap between the two Frame models, and the card moves between your SteamOS devices while internal storage stays put. Internal storage is faster, so if you want the quickest possible loads for your most-played titles, the 1TB model still has a case — but for storing a big library, the card is the better value.
What size microSD card should I get?#
512GB is the sweet spot for most players — enough for a solid rotation of games without overpaying. Go 1TB (the Lexar Play) if you keep a large library installed and don't want to manage space. Below 256GB fills up fast with today's game sizes.
What do A2, U3 and V30 mean, and which matters here?#
They're speed ratings. U3 and V30 guarantee sustained write speed for installing large games. A2 is about random reads and writes — the small-file access that affects how quickly levels and menus load. Because the slot caps sequential speed, A2 is the rating that still makes a real difference, and all three picks are A2.