SanDisk256GB microSD Express Card - Works with Nintendo-Switch 2, Up to 880MB/s Read, Up to 650MB/s Write, 210MB/s Sustained Write, U3, C10 - SDSQXFN-256G-GN4NN

Update 06/07/2025, Comparing to Onn's Express 256:There is a new budget microSD 256 Express card from Onn that appeared in retail this week coinciding with the launch of the Switch 2. It claims to support up to 800MB/s reads and 600MB/s writes. I picked one up to compare. With larger stress tests (Random reads and writes going up to 5GB instead of the 1GB test I show here), this SanDisk can see its transfer rate drop to a minimum of 400GB/s on writes. For the Onn device, on writes the rate drops to 200MB/s typically, but sometimes as low as 150MB/s as the firmware seems to have trouble keeping up (it stalls completely), nearly 3 times slower on average than the SanDisk. What's worse is that it drops to 400GB/s even for transfers as small as 2GB, 300GB/s for 3GB, and 200GB/s from there on up, while the SanDisk still manages to hold minimum 600GB/s. Keep in mind that most larger games for the Switch 2 are about 20GB or more, and there are a few 64GB or larger. I do not currently own a PNY card to test, but online evidence suggests that it too is slower than the SanDisk, but may be faster than the Onn device. With the way the Onn card stalls on writing, literally stopping occasionally for upwards of a second while testing, I could never recommend it. You get what you pay for with the SanDisk. Full review follows.REVIEW:During play, the Onn express card may be able to keep up due to small transfers and minimal loads, but its stalls will affect things, and during download and game management on the Switch 2, you will definitely see a time impact, probably significant. The good news is that the Onn express card was able to hold up on read tests without stalls, with the same 750MB/s as the SanDisk, but it never really went above 750MB/s for even smaller transfers while the Sandisk peaked at about 990MB/s, above their claimed rate. I am sure some caching was involved in that number, but the system caches the Onn in the same way, so there is a significant difference.Great high-speed card if you have a reader that supports Express. This card also outperforms even on a standard controller due to its rapid response time and excellent IOPs (measure of the number it can handle per second). Does well enough to be considered as an external drive on the Mac, though an M.2 reader enclosure will outperform it on specs. Can't beat it for portability.For sustained throughput on the SanDisk Express reader, this can't be beat, easily outperforming any other card I have from 4X to 20X faster. Camera file transfers happen at about 1GB/s. No drivers needed for any recent OS, though Ubuntu has a recent bug that will prevent those devices from attaining full speed unless an external Express-capable reader is used.

I used h2testw to confirm successful write & read+verify functionality before inserting it into the Switch 2 and encountered no problems. I just had to wipe the card which required a small Switch 2 update and restart. After I was able to move games over and play them without issue. This is day one, so no idea yet what the longevity of the card will be. If I encounter issues I will plan to loop back and note them.

Why did you pick this product vs others?:Need more 256 is not enough but is something

I’m using this microSDXC card in a Nintendo Switch 2, which requires this format for expanded storage. Setup was seamless. It was recognized instantly and I moved on without a hitch.I’ve read that the Switch 2 actually loads games faster from memory than from game cartridges, so having a high-capacity card like this is more than just convenient—it’s a performance boost.Once installed, it just works. I probably won’t think about it again for years, and that’s exactly what I want from memory: reliable, invisible, and fast.

Works perfectly in the Nintendo Switch 2!! Does not offer any performance increase unless the slot specifically supports microSD Express! Performs the same as microSDHC in a Ayaneo handheld. In the Nintendo switch it definitely feels like almost a gigabyte a second.

Got more storage for my Switch 2. Can’t wait till they come out with a 1tb version.

Yes, this is the memory card for the Switch 2. It's as easy as sliding in a Switch 2 game cartridge in the Switch 2.

Works perfect on my Nintendo Switch 2. I was worried there might have been issues when I was doing the data transfer from my Nintendo Switch 1 to my Nintendo Switch 2 due to me having a lot of games installed, but the data was placed on the new SD card with no issues. Would recommend for the Nintendo Switch 2.