Why bother with an external SSD
The Steam Deck’s 64 GB eMMC tops out at near 90 MB/s.
A usb3.2 gen2 portable SSD like KingSpec’s US201 (rated for up to 1 030 MB/s sequential reads) shrinks a 100 GB game’s first boot from minutes to seconds. Snap in a dual-plug drive from portable-SSD maker King Spec, such as its US201, then flip the captive cable to drop saves or footage onto a desktop later—no adapter required. In short, the Deck already has the fast lane; an external SSD finally lets you use it.
How we timed our load screens
We tested a factory-fresh 64 GB Steam Deck running SteamOS 3.7.13. The handheld sat in Valve’s powered dock to keep thermals stable, while Wi-Fi, Bluetooth, and the gyro stayed off, and brightness held at 50 percent.
- Games: Elden Ring, Baldur’s Gate 3, Cyberpunk 2077, Mortal Kombat 1
- Storage pools: stock eMMC, a 256 GB SanDisk Extreme microSD, and a 512 GB KingSpec US201 portable SSD on the Deck’s USB 3.2 Gen 2 port
- Prep: cleared shader caches and patched every title to its July 9, 2025 build before each run
- Timing method: pressed Play, waited for the first interactive prompt, ran five trials per drive, dropped the single outlier, and averaged the remaining four
- Extra logs: captured fan speed, surface temperature, and battery draw for the thermals section
What the stopwatch saw
Across all four titles, the external drive cut load time by about 45 percent compared with microSD and 63 percent compared with the built-in eMMC. Because assets arrive sooner, the Deck’s fan settles near 5 500 rpm instead of roaring past 6 800 rpm. Boot-to-battle now fits inside a quick coffee sip, not a coffee break.
Build it for under $100
Cutting load-screen time costs less than buying a new release. Prime Day trackers spotted 1 TB Gen 2 portable SSDs under $70, so we chose a 512 GB model plus two small accessories to stay below the hundred-dollar mark.
|
Item |
Budget pick |
Street price |
Why it matters |
|
External SSD |
KingSpec US201 (512
GB) |
$59 |
Dual USB-C/USB-A
connector lets the drive hop from Deck to desktop without an adapter. |
|
Right-angle USB-C
cable (20 cm, 10 Gbps) |
JSAUX |
$9 |
Keeps the plug
flush, so trigger fingers stay clear. |
|
Mounting strap |
DIY Velcro roll |
$6 |
Holds the drive
behind the vents without blocking airflow. |
Prices captured July 9, 2025; expect small changes after the sale.
Setup steps
Step one: give the SSD a fresh ext4 home
- Connect the drive. Insert the portable SSD into the Deck’s USB-C port, then open Settings ▸ Storage. A gray Generic external entry appears within one second.
- Format it. Highlight the drive, press A, and choose Format. Select ext4; the Deck’s kernel writes to ext4 faster and reduces corruption risk during power loss.
- Wait 30 seconds. A 512 GB volume finishes formatting in 30 seconds. When the progress bar turns blue, SteamOS mounts the drive and marks it Ready.
Step two: point Steam at the new drive
- Set it as default. In Settings ▸ Storage, highlight the SSD, press A, and choose Set as default. Every new download now lands on the external drive.
- Move existing games. Open Manage Steam Library Folders, tap the + icon, pick the SSD, select any installed title, and press Move. The Deck copies data at about 850 MB/s, so a 60 GB game shifts in less than a minute.
- Verify the transfer. When the progress bar finishes, Steam labels the game Ready to play, confirming the library now lives on a faster drive.
Step three: move large games on wall power
A 60 GB transfer such as Elden Ring drains approximately 7 percent of a full battery. Dock the Deck, or connect any 45 W USB-C charger, before you press Move. Wall power lets the APU run at full speed, shortens copy time by one to two minutes, and keeps surface temperatures lower.
If no dock is available, dim the screen, enable Airplane Mode to silence Wi-Fi and Bluetooth, and begin the transfer.
Step four: copy games from a microSD card
- Open Desktop Mode. Boot the Deck into Desktop Mode, insert your microSD card alongside the SSD, and open Dolphin. Two drives appear in the left pane.
- Move the game folder. In the card’s steamapps/common directory, drag the game folder to the SSD’s matching location and choose Move. The copy runs at approximately 300 MB/s, almost ten times faster than downloading again. The copy runs at approximately 300 MB/s, almost ten times faster than downloading again (see our NVMe vs SSD guide for how PCIe lanes unlock even higher speeds).
- Verify in Gaming Mode. Return to Gaming Mode, let Steam verify the files, and launch.
Keep it tight, keep it cool
- Route the cable. Guide the right-angle USB-C lead under the volume rocker so it hugs the spine.
- Seat the drive. Rest the SSD on the shelf below the exhaust grille. Thread a 25 mm Velcro strip through two vent slots, leaving a 2 mm gap for airflow.
- Optional mount. Deckmate pucks or a snug 3-D-printed bracket twist on and off in seconds.
Done correctly, the assembly weighs less than 40 g (1.4 oz) and never blocks a vent, trigger, or grip.
Battery and thermals reality check
A 30-minute loop of Elden Ring on the stock eMMC used 22 percent of the Deck’s 40 Wh battery. Running the same scene from the external SSD used 18 percent, extending playtime by about 20 minutes.
Fan speed settled near 5 500 rpm instead of spiking past 6 800 rpm. Surface temperature dropped from 69 °C on eMMC to 62 °C on SSD, while the drive itself held at 47 °C.
SSD FAQ
Ext4, exFAT, or NTFS: does it really matter?
Format the drive as ext4. SteamOS writes to ext4 natively, so game updates finish faster and recover gracefully after power loss. exFAT helps only if you move the drive to Windows every day. NTFS relies on slower helpers in Linux, which removes the speed you just paid for.
Do I need to run TRIM manually?
No. SteamOS runs fstrim every week on each mounted ext4 volume, including your SSD. If the drive sits unused for months, plug it in and run sudo fstrim -v /run/media/mmcblk0/steamssd from Desktop Mode.
Will docking the Deck slow my SSD?
Not with the official Valve dock, or any hub that offers at least one USB 3.2 Gen 2 port beside HDMI. In testing, Baldur’s Gate 3 loaded only half a second slower on a 1080p monitor than in handheld mode, and a 20 GB file copy still averaged about 870 MB/s.
Could a SteamOS update make the SSD disappear?
Unlikely. Since SteamOS 3.7, USB ext4 volumes remount automatically. If your games vanish, open Desktop Mode, run lsblk, then sudo mount -a or unplug and replug the drive.
What is the safe way to disconnect the SSD?
Press the Steam button, choose Power ▸ Safely Remove External Drive, and wait for the confirmation pop-up. Most enclosures turn off their activity LED within two seconds; that is your cue to unplug.
Conclusion
Spend one evening, and less cash than a new AAA release, to cut minute-long logo crawls to under 30 seconds, free up the Deck’s 64 GB eMMC, and gain a pocket drive that plugs into any USB port. Small swap, big payoff.
Launch your favorite game, time the load, and share your before-and-after numbers in the comments. Have questions, or a clever mounting idea of your own? Drop those too. If this guide saved you a few seconds, subscribe to the TechyFlavors Friday newsletter for more how-tos every week.
