The fastest no-tools way to give a Steam Machine more game storage is a portable SSD on the rear USB-C port — plug it in, format it once, and your library grows by terabytes without ever opening the case. All three picks here are 10Gbps portable drives: the Samsung T7 Shield is our best overall, the Samsung T7 is the same rated speed without the armor, and the SanDisk Extreme is the pick if the same drive also travels in a bag.
One spec decides this whole purchase, and it saves you money: the Steam Machine's fastest external port is the rear USB-C 3.2 Gen 2, which tops out at 10Gbps (~1,000 MB/s real-world). That means the expensive 20Gbps and 40Gbps drives, like the Samsung T9 or a Thunderbolt enclosure, get no faster here. Don't pay for speed the port can't use. A good 10Gbps drive like the three below already saturates the connection, so the money you save belongs in capacity instead.
And to set expectations honestly: an external drive is the big-library option, not the speed option. For the fastest possible loads, the internal M.2 drive is still king — that upgrade is covered in our best SSDs for the Steam Machine comparison. The external drive is where the rest of your backlog lives, one cable away.
Who this comparison is for#
- Anyone whose Steam Machine drive is full and who wants a lot more space without opening the console or re-imaging anything.
- Players with a big backlog who'd rather keep everything installed than download games again over a slow connection.
- Anyone choosing between a microSD card and an external SSD for overflow. The SSD is roughly 10 times faster, and the card hides in the front slot. Here are the best microSD cards for the Steam Machine.
Already have a spare NVMe drive, like the one left over from upgrading the Machine's internal SSD? You don't need a whole portable SSD. Here are the best NVMe enclosures for the Steam Machine.
How we picked#
- 10Gbps drives only. The rear USB-C port is USB 3.2 Gen 2, so every pick is a 10Gbps drive that saturates it. We deliberately skipped 20Gbps, Thunderbolt and USB4 drives. On this console they're no faster, and they cost meaningfully more.
- The makers' own drives, one speed class. Game installs are long sequential writes and gameplay is lots of reads. All three are NVMe drives from the storage makers themselves, rated at the same 1,050 MB/s reads over the same USB 3.2 Gen 2 interface.
- Built to live behind (or off) a console. A drive that hangs off a living-room machine gets knocked, unplugged and carried. Every pick here is rated for drops and rough handling — no bare-plastic drives.
- Capacity that fits a modern library. All three scale to 4TB, which is where an installed-everything backlog actually fits.
Getting it working (one-time, five minutes)#
SteamOS treats an external drive as a full game library. Format the drive to ext4 from Desktop Mode (Linux's native filesystem — the one SteamOS handles best for game libraries), then add it as a Steam library folder in Storage settings. From then on SteamOS auto-mounts it, and games install to it like any other drive. Use the rear USB-C port for the full 10Gbps. The front USB-A ports are 5Gbps, fine in a pinch and still several times faster than a microSD card, and the rear USB-A 2.0 pair is for controllers and dongles, not storage.
Samsung T7 Shield — Best Overall#
The T7 Shield is the default answer for exactly this job: a 10Gbps drive with Samsung's own SSD controller, rated at 1,050 MB/s reads and 1,000 MB/s writes — which is the rear USB-C port's practical ceiling, so nothing faster would show up in load times anyway. Samsung builds the NAND, the controller and the firmware in-house and backs the drive with its own Magician software for health checks and firmware updates, which is the boring kind of reassurance you want from the drive your library lives on. Magician doesn't run on SteamOS, so you'd plug the drive into another computer for those.
The "Shield" part earns its name in a living room. The rubberized body is IP65-rated against dust and water and rated for drops from 9.8 feet (3 metres), which is precisely the insurance you want for a drive that dangles off a console shelf, gets yanked out by a cable snag, or rides to a friend's place. Reformatted, the same drive also works as fast editing or backup storage on a PC or Mac. We've reviewed it in depth in our Samsung T7 Shield review — it earned its spot there for the same reasons it wins here.
Key specs#
Interface : USB 3.2 Gen 2 (10Gbps) over USB-C — matches the Steam Machine's fastest port
Rated speed : Up to 1,050 MB/s read / 1,000 MB/s write
Durability : IP65 dust/water resistance, 3m drop rating, rubberized body
Capacities : 1TB / 2TB / 4TB
In the box : USB-C to C and USB-C to A cables
Best for : The set-and-forget library drive that can also take a beating
Bottom line. The port's full speed, Samsung's own SSD controller and flash, and an IP65 body rated for 3-metre drops. Buy the 2TB and stop thinking about storage.
Samsung T7 — Also Great#
The T7 is the Shield's speed without the armor. It's rated for the same 1,050 MB/s reads and 1,000 MB/s writes, and like the Shield it uses Samsung's own SSD controller, flash and firmware. The port caps both at 10Gbps anyway, so what separates them is the shell, not the load times.
Instead of rubber, the T7 has a solid aluminum body rated for falls up to 6 feet, against 9.8 feet for the Shield, and it has no dust or water rating where the Shield is IP65. In exchange it's lighter and slimmer, about 58 g and 8 mm thick against 98 g and 13 mm for the Shield. On a shelf behind the console, that's usually all the protection a drive needs. If it also rides to the beach or a friend's place, get the Shield. Both come with USB-C to C and USB-C to A cables, and both have password protection.
Key specs#
Interface : USB 3.2 Gen 2 (10Gbps) over USB-C
Rated speed : Up to 1,050 MB/s read / 1,000 MB/s write
Durability : Aluminum unibody, rated for falls up to 6 feet, no IP rating
Weight / thickness : 2 oz, 0.3 in (about 58 g, 8 mm)
Capacities : 1TB / 2TB / 4TB
In the box : USB-C to C and USB-C to A cables
Best for : A library drive that stays on the shelf behind the console
Bottom line. The same rated speed as the Shield and Samsung's own SSD controller and flash, in an aluminum body instead of rubber armor. Pick it when the drive lives behind the console rather than in a bag.
SanDisk Extreme Portable SSD — Best for Travel#
The SanDisk Extreme is the third member of the same 1,050 MB/s club, with one physical feature the other two lack: a molded carabiner loop. That sounds trivial until the drive splits time between the living room and a backpack — clipped to a bag strap or a keyring, it's the drive you actually take places. The silicone-shelled body is IP65-rated against dust and water and rated for 3-metre drops — SanDisk requalified the drive upward from its original IP55 and 2-metre ratings, so it now matches the T7 Shield on paper and shrugs off the kind of handling that scuffs bare-metal drives.
Performance-wise it matches the two Samsungs: the same interface and the same 1,050 MB/s read rating, so the port is the limit for all three.
Key specs#
Interface : USB 3.2 Gen 2 (10Gbps) over USB-C
Rated speed : Up to 1,050 MB/s read / 1,000 MB/s write
Durability : IP65 rating, 3m drop rating, silicone shell, carabiner loop
Capacities : 500GB / 1TB / 2TB / 4TB / 8TB
Extras : Loop for clipping to a bag or keyring
Best for : A library drive that also commutes — console at home, fast storage on the go
Bottom line. Same speed as the others plus the most portable-friendly design. Buy it when the drive travels as much as it stays.
Which one should you buy?#
For most people, buy the Samsung T7 Shield 2TB. It saturates the Steam Machine's rear USB-C port, runs on Samsung's own NAND, SSD controller and firmware, and its IP65 body plus 3-meter drop rating make it the drive you never worry about. It's the set-and-forget pick.
If the drive will live on a shelf behind the console, buy the Samsung T7. It carries the same 1,050 MB/s rating as the Shield in a lighter, slimmer aluminum body rated for 6-foot falls, without the Shield's rubber armor and IP65 rating.
If the drive will live half its life in a backpack, buy the SanDisk Extreme. The carabiner loop and silicone shell make it the natural traveler.
Whichever you pick: use the rear USB-C port, skip anything marketed as 20Gbps, Thunderbolt or USB4 for this console, since none of it gets past 10Gbps here, and remember the split. The internal M.2 drive is the speed upgrade (best SSDs for the Steam Machine), the microSD slot is the cheapest overflow (best microSD cards), and the external SSD is the big-library sweet spot between them. For the rest of the setup, here are the best Steam Machine accessories.
FAQ#
Can the Steam Machine run games directly from an external SSD?#
Yes. SteamOS supports full game libraries on external drives: format the drive to ext4 in Desktop Mode, add it as a library folder in Storage settings, and install games to it like any other drive. SteamOS auto-mounts it from then on. It won't match the internal drive, but over the rear 10Gbps USB-C port it reads about ten times faster than the microSD slot allows.
Should I buy a Thunderbolt, USB4 or 20Gbps drive instead?#
No — not for this console. The Steam Machine's fastest external port is USB 3.2 Gen 2 at 10Gbps, so a 20Gbps drive like the Samsung T9 runs no faster than the drives here, and a Thunderbolt or USB4 drive gains nothing either. You'd pay a real premium for zero extra speed.
Which port should I plug the drive into?#
The rear USB-C port — it's the 10Gbps one. The two front USB-A ports are 5Gbps: fine for a temporary hookup and still miles faster than a microSD card, but they halve what these drives can do. The two rear USB-A 2.0 ports are for controllers and dongles, so don't put storage there.
External SSD or microSD card for extra Steam Machine storage?#
The SSD is roughly ten times faster, because the Steam Machine's card slot is UHS-I (~100 MB/s real-world). A microSD card is the cheap overflow that hides in the slot. If you mostly store smaller or older games, a card is fine. If you want one drive that treats your whole backlog like a real library, get the SSD.
What capacity should I get?#
Get 2TB. It holds a good rotation of modern 100GB-class games. Go 4TB if you really keep everything installed. 1TB works as a starter but fills faster than you'd think.
Do I need to format the drive, and will it still work on my PC?#
You'll want ext4 for the Steam library, and Windows can't read ext4 out of the box — so treat the drive as dedicated to the console once it's set up. If you need one drive that moves between a Windows PC and the Machine for regular files, keep a separate partition or a different drive for that. Mixing both jobs on one filesystem is where people get burned.