Will a microSD card lower my FPS?

No — once a level is loaded, your FPS comes from the GPU and CPU, not the storage. What a slow card affects is load times and shader compilation , so you'll see longer loading screens and occasionally more texture pop-in on games that stream assets. For indies and most single-player titles you won't notice in actual gameplay.

Can I run games directly off a USB SSD without reinstalling SteamOS?

Yes. A USB SSD is just an extra install location — format it in SteamOS and pick it as the target when you install or move a game. No OS reinstall needed, unlike the internal NVMe upgrade. That's why the external SSD is the low-risk, high-reward option for most people.

Does upgrading the internal NVMe void my warranty?

It may, and it involves opening the case — so check Valve's official documentation before you start and follow their exact procedure. If you'd rather not risk it, a USB SSD gives you nearly the same speed with no disassembly and no warranty questions. Reserve the internal swap for when you specifically want one clean, fast drive.

How do I move an already-installed game to a new drive?

Go to Settings > Storage , select the game, and choose Move to the new drive. Steam relocates the existing files instead of re-downloading them, so it's quick and safe. This makes it easy to shuffle your current game onto fast storage and push your backlog to microSD.

Steam Machine Storage: microSD vs External SSD vs Upgrading

A 512 GB Steam Machine sounds roomy until you install three modern games. At 80–150 GB each for AAA titles, you can fill that drive in an afternoon. Here is the short version: use a microSD card for indie and older games you don't mind loading a few seconds slower, a USB external SSD for a big library of big games, and an internal NVMe upgrade when you want one fast drive that holds everything and never think about it again. Most people end up doing two of these three.

This guide covers each option honestly — what's fast, what's cheap, what's worth your money — and ends with a decision rule you can apply in five minutes.

How much storage do you actually need?

Open Steam, go to Settings > Storage, and look at what's installed. Be realistic about your active library — the games you actually play in a given month, not the 200 you own.

A rough budget:

Small library (5–8 games): 512 GB is tight but workable if you uninstall as you go.
Medium library (10–15 games, mixed sizes): you want 1–2 TB total.
Large library or big modern AAA: 2 TB+ and you'll still juggle.

Keep in mind SteamOS, Proton, and shader caches eat 30–40 GB before you install anything. Your "512 GB" drive gives you closer to 470 GB usable.

Option 1: microSD card (cheap and surprisingly fine)

A microSD card is the cheapest way to add space. Steam Machine takes the card, formats it in SteamOS, and treats it as another install location you pick per game.

The honest tradeoff is speed. A good UHS-I card reads around 100 MB/s; a fast NVMe drive reads 10–50× that. In practice that means longer load screens and slower initial shader compilation, not lower in-game FPS once a level is loaded. For many games the difference is a few extra seconds at a loading screen.

Good on microSD:

Indie games, 2D games, pixel art, roguelikes
Older titles and emulated libraries
Games you play casually and don't restart constantly

Bad on microSD:

Open-world AAA that streams assets continuously (Cyberpunk, Starfield-class)
Anything with frequent fast-travel or level reloads
Games where you'll notice texture pop-in

Buy a reputable UHS-I card (A2-rated is a nice-to-have but real-world gains are small). A 512 GB card is cheap and roughly doubles your space for the price of a few coffees. Format it inside SteamOS, not on a PC, so Steam recognizes it.

Option 2: USB external SSD (the sweet spot for big libraries)

This is the best balance for most people who've outgrown the internal drive. A USB SSD plugged into the Steam Machine is dramatically faster than microSD and big enough to hold a real library.

You have two tiers:

USB SATA SSD (2.5"): ~550 MB/s, cheap per terabyte, plenty fast for almost every game. This is the value pick.
USB NVMe SSD (enclosure): 1,000+ MB/s over USB. Faster, pricier, and the gains over SATA are small in real gameplay.

For a living-room console, a 1–2 TB external SSD tucked behind the unit is clean and effective. Load times land close to the internal drive for most titles. The only downside is a cable and a box on your shelf.

Format it in SteamOS (Settings > Storage > the new drive > Format) so it becomes a selectable install location. Then move or install big games to it. A USB SSD is also trivial to unplug and carry to another machine — handy if you also have a gaming PC.

Option 3: Upgrade the internal NVMe (the clean fix)

If you want one fast drive and a tidy setup, replace the internal NVMe SSD. This gives you full internal speed across your whole library and no dangling hardware.

What to know before you open it:

The Steam Machine uses a standard M.2 NVMe drive. Buy a 1 TB or 2 TB drive from a reputable brand.
This may affect your warranty and requires opening the case — check Valve's official guidance and follow it exactly. Don't force anything.
You'll need to reinstall SteamOS to the new drive via a recovery image, then re-download your games.

Steps in brief:

Back up save data (most syncs via Steam Cloud, but confirm per-game).
Power down fully and unplug.
Open the case per Valve's instructions, swap the M.2 drive.
Flash SteamOS from a USB recovery image.
Sign in and reinstall games.

This is the most work but the best end state: maximum speed, maximum capacity, nothing hanging off the back. If you're comfortable building or upgrading PCs, it's straightforward. If opening hardware makes you nervous, an external SSD gets you 90% of the benefit with zero risk.

What to keep on fast storage vs microSD

A simple sorting rule once you have a fast drive plus a microSD card:

Internal NVMe / USB SSD (fast):

Your current main game
Open-world and asset-streaming AAA
Competitive shooters where load time matters
Anything you restart or fast-travel in constantly

microSD (slow but fine):

Indies, 2D, retro, emulators
Story games you play in long sessions (load once, play for hours)
Your backlog and "might play later" pile

You can move a game between drives anytime in Settings > Storage without re-downloading the whole thing — Steam relocates the files.

A simple decision rule

Just need a little more room, cheaply? Add a 512 GB or 1 TB microSD. Done in two minutes.
Big library, want most games fast? Buy a 1–2 TB USB SATA SSD. Best value for the most people.
Want one fast drive and a clean setup, and you're comfortable opening hardware? Upgrade the internal NVMe to 2 TB.
Not sure? Start with a USB SSD. It's reversible, fast, and you can carry it elsewhere.

Most owners land on USB SSD for the big stuff + microSD for the backlog, and never touch the internal drive. That combination is cheap, fast where it counts, and requires no disassembly.

Want to know which games actually need the fast tier? Check our /games playability ratings and the methodology behind our load-time notes. Still deciding between devices? See which device is right for you.