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.

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

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!)

It works fine as expected.

Great product works fine with switch 2

Sandisk has always been known for their quality and this SD card is no different. Provides rock solid performance for my switch 2 with great read/write speeds. I just popped it into my switch 2 and it was formatted quickly by my switch. Works out of the gate and I appreciate the convenience of that.

Works in my Switch 2

This is the required type of microSD for the Nintendo Switch 2. It’s really too bad that SanDisk only makes them at a max size of 256GB right now. I plan to buy the 1TB version once they start selling it. SanDisk is the most reliable microSD on the market right now. I don’t trust anyone more than them. I’ve never had to worry about them at all. Functional, decent value, fast speeds, good enough storage for now on my Switch 2, and easy to install under the Switch 2 stand.

Nintendo Switch2のために購入しました。 256ギガのMicroSD Expressカードは本体と同時に買ったのですがすぐに容量がいっぱいになってきたので新たに購入しました。Switch1の時はゲームデータを消去したことはなかったけれど、Switch2はクリアしたゲームは積極的に消さないとすぐに一杯になりますね。SanDiskのこれはスピードも動作も問題なく、今のところ購入して良かったと思います。

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.

Bought this for a Switch 1 system and it’s performed flawlessly. Load times are quick, games run smoothly, and I haven’t noticed any delays, lag, or compatibility issues at all. It installs easily, is recognised instantly, and just quietly gets on with its job. The speed is clearly there — everything feels responsive, downloads handle well, and it doesn’t struggle even with larger titles. Build quality is what you’d expect: solid and dependable. If you want extra storage that actually keeps up with your console rather than slowing it down, this is a great choice. Fast, stable, and completely reliable.

All the bytes tested for defects, all working.