256GB 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.

Excellent card, very fast when used with the Lexar Express reader. Works well with DJI enterprise drones. A bit expensive, but if you're moving large amounts of data this will pay for itself pretty quickly in the time saved. Was a bit challenging to order unfortunately and I seem to have about every other order cancelled due to order queueing issues.

Using it for storage and it works as expected. Fast enough and no issues so far. Easy to set up and reliable.

I bought this because I was preparing to get a Switch 2, and I buy my games almost entirely digitally, meaning I wanted to have as much storage space as was feasible. At first, I thought the price was a bit much, but I live in the United States and tariffs suck, so I resigned myself to paying it as an “Unavoidable tax.” Little that I know that this was so expensive because it’s way bigger than you think it is. I was expecting switch games to be at least half as big as they are on other consoles from a file size perspective. Boy was I surprised when I downloaded half my entire switch library onto this thing and it’s not even a fourth of the way full! This is great! I don’t think most people are going to need a size this big, in fact, I think most people are going to need something not even half this size. The write speed is pretty fast, and it’s made to be compatible with the Switch 2, so no problems there. If you are like me, and do everything entirely digitally and hate having to re-download things on a whim just to replay them, then sure, spring for this size if you’ve got the cash. Otherwise, I would definitely consider down scaling to something smaller for cheaper. It’s great, but you don’t need it to be this big (from a Storage standpoint, the stick itself is very, VERY tiny!)

Works exactly as expected for a high performance micro SD card.

Used in Switch 2, this has been super-easy to install, format and has been working very well. No hickups, very fast. Reasonable price for the new Express card. Will be my go-to for other applications, too

Great product works fine with switch 2

Worked great in my new Switch 2. System accepted quickly, no issues. Games load lightning fast, no hiccups. I always get great performance from Sandisk memory, a little more cash but well worth it!

Switch2購入サイトで品切れのため購入。対応してたので良かった。他の使い道は未検討

This SanDisk microSD Express 512 GB card delivers impressive performance and clearly stands out from standard microSD cards. Read speeds are extremely fast when used in compatible devices, making it ideal for high-resolution video, large file transfers, and demanding applications. Build quality is excellent, as expected from SanDisk, and reliability has been solid so far. Just be aware that to fully benefit from the speed, you need a device that supports microSD Express, otherwise it will fall back to regular microSD performance. Overall, a great choice if you want maximum speed and future-proof storage. Highly recommended for supported hardware.

Fajna, szybka karta do Nintendo Switch 2, ale chyba trzeba pomyśleć o 1 GB, o 256 nawet nie myślcie.

Gostei muito. Estou usando no Nintendo Switch 2

Excelente opción, buena calidad, producto original, compatible con Nintendo Switch 2. Lo uso para aumentar el espacio de almacenamiento de mi consola y funciona perfectamente, la transferencia de datos a la tarjeta es muy rápida.