If you’ve been cranking through Nintendo Switch 2 games, storage is probably getting pretty tight. 256GB of internal storage is uncharacteristically generous for Nintendo, sure, but with great power comes great file sizes. The console’s first-party games are svelte, but third-party games like Street Fighter 6 Years 1-2 Fighters Edition (50.8GB) or Cyberpunk 2077: Ultimate Edition (60.2GB) eat up their fair share of space. If you’re hitting that wall, it’s time to expand your storage!
Unfortunately, you can’t re-purpose any old microSD card for the console – it requires MicroSD Express, a faster version of the miniature solid-state storage medium. That means less waiting to load games or when shuffling files between your Switch 2’s internal storage and your added microSD card. While these are usually much more expensive than traditional microSD cards, the Onn MicroSD Express card is the cheapest of them all: A $35.77 microSD card with 256GB of space that’s sold under Walmart’s in-house budget tech brand.
Throughput
I’ve been rolling with a 256GB Onn MicroSD Express card since launch because it was cheap and available when I got my Switch 2 – you could say it was (ahem) Onn time and under my budget. Walmart claims this card has up to 800MB/s read throughput (how fast it can serve its data) and up to 600MB/s writes (how fast data can be written to it). The Switch 2’s internal storage, by contrast, uses soldered-on UFS 3.1 flash storage, with up to 1,200MB/s writes and up to 2,100MB/s reads.
Whoa, neat numbers, right? Yeah, but don’t put too much stock in them; they’re referring to sequential data transfers of large, contiguous files. That gives data rates a nice, long runway to climb. Game files are really just packages that contain lots of smaller files, leaving the transfer process constantly starting and stopping and adding a massive throughput penalty.
Performance: File Transfers
That doesn’t mean microSD Express isn’t a huge improvement over the original Switch’s standard microSD. It took more than 21 minutes to transfer my copy of the 17.2GB Super Smash Bros. Ultimate from my original Switch OLED to the Samsung Evo microSD card, and 9.5 minutes to move it back. On the Switch 2, meanwhile, it took just shy of 5 minutes to transfer to the Onn card and under four minutes to transfer back to the Switch 2 itself.
That’s a big time savings! I also found it took 7 minutes and 20 seconds to move Mario Kart World, which takes up 24.6GB on my console, to my Onn card. That’s a data-writing rate of 55.91MB/s. Moving the game back took 319 seconds, at a rate of 77.12MB/s. Transferring the 8.6GB Donkey Kong Bananza to the card took just 2 minutes, 45 seconds (52.12MB/s), and I waited 3 minutes, 18 seconds (76.11MB/s) for it to transfer back.
Those results were gathered after a couple months of using the card. After wiping it and re-testing these transfers with Mario Kart World, write speed jumped to 71.10MB/s, and read speed to 91.45MB/s. That makes sense if the card’s data had become fragmented from use – wiping it and reloading my game files onto it may have helped things.
Performance: Load Times
The relatively quick read rate means less time waiting to actually play your games, although it’s not as fast as loading them from internal storage. On average, it took about 20 percent longer to get to the title screen of games stored on the card versus natively on the Switch 2, although it varied from one game to another. Loading from the Onn card, Donkey Kong Bananza took 25.74 seconds, and Mario Kart World took 20.54 seconds. Re-testing after wiping and reloading the card, Mario Kart still took about as long, while Bananza loaded in 21.43 seconds. From internal storage, I only waited 20.86 seconds for Bananza and 17.46 seconds for Mario Kart.
It was much closer for other games – the Switch 2 edition of No Man’s Sky took 15.37 seconds to load from the microSD Express slot, and 13.98 seconds from internal storage. It was hardly slower to load The Legend of Zelda: Tears of the Kingdom; 9.78 seconds versus 8.88 seconds. While Super Smash Bros. Ultimate came in at 16.32 seconds from microSD Express and 15.7 seconds from internal storage.
I saw the biggest performance gulf with Fast Fusion – a cheap antigrav racer you really should play if you’re an F-Zero fan – loads as fast as its cars race from internal storage at 7.32 seconds, practically lapping the sluggish-by-comparison 11.71 seconds from the Onn card.
I’m in the midst of comparing the Onn card with PNY’s microSD Express card, and its results were better than Onn’s at first. It initially had higher read throughput, leading to faster game load times and quicker transfers to the Switch 2 from the card, while write throughput was on par with the Onn card. After wiping and reloading the Onn card, though, things mostly evened out.
You Get What You Pay For
These results differ from what the folks at Digital Foundry saw back when the Switch 2 launched. In general, system load times versus microSD Express load times didn’t have as much variance, and in their testing, a Nintendo-supplied SanDisk microSD Express card they were using actually called games up a tiny bit faster than the Switch 2’s internal storage. A SanDisk microSD Express card is twice as expensive for the same storage tier, so you’d hope for better performance!
Should you pick the Onn card anyway? It’s not the best microSD Express card you can get for your Switch 2, but I mean, that $35 price tag for 256GB is pretty hard to pass up. And although it may be slower than cards that cost twice as much, it’s not terribly so, especially after wiping and refilling the card.
Wes is a freelance writer (Freelance Wes, they call him) who has covered technology, gaming, and entertainment steadily since 2020 at Gizmodo, Tom's Hardware, Hardcore Gamer, and most recently, The Verge. Inside of him there are two wolves: one that thinks it wouldn't be so bad to start collecting game consoles again, and the other who also thinks this, but more strongly.
