SanDisk 64GB Extreme microSDXC UHS-I Memory Card with Adapter - Up to 160MB/s, C10, U3, V30, 4K, A2, Micro SD - SDSQXA2-064G-GN6MA

Got the 512 GB model to expand on the Steam Deck's admittedly limited storage. Even if you got the largest storage model of the Deck (512 GB) it can fill up quickly. Games are just bigger nowadays. I think the newest Call of Duty is like 150 gigs.Just like every storage manufacturer, they advertise the storage in "GB" instead of "GiB", so when you actually plug it into a computer you lose some space in the conversion. In this case, after you format it on the Steam Deck (ext4 I believe) you end up with 468.2 GB of usable space. Which admittedly is a tiny bit bigger than the Deck's own 465.3 GB of usable space on the 512 model. It seems like every storage mfr. has their own way of making this GB/GiB calculation, and it's just plain annoying how they always favor giving you less storage than it says on the label. It's so common now it's pretty much standard practice with them, so what can you do. But losing 9% of your storage space is never fun, so it's always worth complaining about again.The largest game I have loaded on this card is Horizon Zero Dawn Complete Edition, which is 73.48 GB. And the stories are true, it loads pretty much just as fast as the Steam Deck's own SSD. The game's intro comes with a few somewhat lengthy cutscenes, and game developers have gotten pretty good at hiding the loading screens in the background now, but still there was absolutely no wait at all between gameplay sections. In fact, I have another older game "Destroy All Humans!" (2005) on the Deck's SSD that has more hard loading screens, and it just "feels" like it takes longer to launch and load new levels than Horizon Zero Dawn on the micro SD card. HZD had a few times where it would stutter during the intro cutscenes, and drop to 20 FPS very momentarily, but for some reason this seemed to clear up after about 30 mins in, and otherwise ran at around 35-45 FPS. Definitely watchable. Gameplay was much smoother, had absolutely no stutters, and ran really consistently at around 40 FPS. Definitely playable.And not all of that may be down to the card. I'm not sure if Horizon Zero Dawn uses pre-rendered cutscenes or not (basically a video file), but it might explain the odd stuttering that only happened during cutscenes, and not during gameplay. However you would think streaming even a 4k video file should be easy, stutter-less task for this card. Another reason could be Steam's own weird download behavior: if you want to download multiple games at the same time to load your new card up, each time you click "Install" on a new game, Steam will interrupt whatever download it was currently working on and immediately start downloading the game you just clicked on, putting whatever it was downloading before into a queue. As far as I know, there's no way to just add games directly to the queue, to have them each download 1-at-a-time uninterrupted. If there is that option I haven't found it yet. (You would think this would be the default behavior anyway.) This means when I clicked on 8 different games to start downloading at the same time, each time I clicked on the next one it would pause the current download at around 1% complete, and only pick it back up again once the last one I clicked on completed. This causes pretty bad fragmentation in your game data, with the first 1% of 8 different games stored at the beginning of the card. But it could explain the rare stuttering in the intro cutscenes that somehow miraculously cleared up after a little while. Solid-state storage is supposed to have much better random IOPS read performance than HDDs, but no matter what when you've got fragmented data you're going to get slower speeds than continuous reads.FYI, you can transfer games between 2 different micro SD cards directly on the Deck. I was using a temporary 64 GB card while waiting until this one arrived, and my Windows computer couldn't read the ext4 or whatever filesystem Deck uses, and I didn't want to mess around with new drivers to get that to work. But with a few USB-C to USB-A adapters and micro SD card reader, it's easy to do on the Deck itself. It won't show up on the Deck's Storage menu of the main interface, so you have to hold the power button down and switch to Desktop mode, where you can use the standard file browser to copy things over. Keep this in mind before you start troubleshooting your wonky series of daisy-chained adapters/card readers because you think they aren't working. And make sure you format the new card first.Another FYI: I had a little scare thinking I bricked my Deck or something when I first installed this card. I made sure to completely shut down the Deck before swapping SD cards, but I think that confused the bootloader. When I turned it back on the Deck had a completely blank, black screen, and Steam didn't load. It turned out the boot order somehow got switched, and it was trying to find the Steam OS on the new microSD card instead of the Deck's SSD. To fix this is easy, while it's off hold 'Volume Down' and click the Power Button - when you hear the chime, let go of the Volume Down button, and you'll be booted into the Boot Manager. There you can fix the boot order, and I haven't had it happen again since. Just search "steam deck recovery" online for more info, Valve has great instructions.

I confess that, in spite of my self-evaluated 'vast technical knowledge', I wasn't thinking about some of the finite life issues that memory cards present. I bought some rather generic barely fast enough SDXC cards for security cameras I installed eight years ago. The first one failed several months ago (based on last recording date) and we didn't discover that until we needed to watch a particular recent event. No recording. Not Good!Decided to step up to better memory cards, and added a tickler to the maintenance schedule to replace the camera cards -before- they lock up. The other five cameras are getting new cards now too. I'm not too interested in having cameras the don't record.

This is one of the fastest traditional MicroSD cards on the market if not THE fastest and performs great at a lot of tasks. I use this in my Asus ROG Ally X(the updated one that doesn't cook MicroSDs) and it is more than enough for emulation up to PS3 as well as older PC games. This is a great way to expand my Ally X's storage without needing an even more expensive SSD than I've already put in it. That it's removable makes it infinitely useful for transferring material from my main PC.I cannot speak for its speed for other uses, however it is the fastest MicroSD card I've ever owned by far. Pretty expensive for the capacity and speed but there is literally almost nothing better for this specific application. Good stuff!

What can I say...I almost always by San Disk. They always work great, and I have never had a problem with them. I am a freelance photographer and take a lot of pictures every year...most of which are on my San dusk cards.

own this memory card for some time now and works great on my gopro.

I haven't had good luck with Sandisk micro SD cards. I haven't had any failures but these are my two issues:1. On large file transfers - more than 1gb - Sandisk tends to overheat and lose transfer speed. This is worse writing TO the card than reading from it. Transfer speeds are stil ok, but nothing like the speeds I get from my USB 3.1 port with a thumbdrive. Several years ago the problem was so severe my files got corrupted even when the on-board thermal protection was throttling my transfer speeds down to 5-10 megabytes per second. In the past two years data loss has ceased to be a problem, and the speed hit on large file transfers is much less severe, although Samsung continues to run faster, in real life big file transfers, than San Disk, at least for me.2. I don't think Sandisk really meets the specs required for "extendable" or "unified" storage on Android, that or it throttles so early the perfomance on small, constant file reads and writes suffers more than it should. I almost always get an error message with their A1 cards on budget (Qualcom 42x chipset) phones complaining the storage is slow and hence not optimal as unified storage. I haven't gotten this error message with my two Fire HD 10 9th gen tablets on this latest A2 iteration, however, which may be a function of the chipsets and memory controller used in these tablets or maybe the upgrade from A1 to A2 makes a difference.I purchased two Fire HD 10's, 2020 editions/9th gen (the second one purchased on Prime Day for just $80, which is insanely cheap) and two of these A2 class Sandisk 128gb micro SD cards.A2 means the memory controller built into the micro SD card should be fast enough to run apps (not gaming apps!) from the card, not just read storage data.The real challenge is for app-rated (A1 or A2) card to handle data reads and writes for multiple apps at the same time. "Same time" is critical - it's not reading a single big file that creates problems for micro SD cards, it's reading small files at nearly the same time to handle the needs of multiple apps running at the same time. The way to avoid any performance issues is to NOT allow the operating system to "move" apps from true internal storage to the SD card. Only data.The first 128gb drive installed perfectly easily in my first Fire as "portable" or "removable" storage but that is not surprising. The second card was installed as "internal storage" in the second Fire glitched several times, crashing once, and not recognized by the tablet as storage at all. I don't know what I finally did to get past the glitches. but as far as I can tell what finally worked was first formatting it as "portable" storage first, rthen ebooting, then re-formatting it as "internal" storage.I was "offered" a chance to move some apps onto the SD card after formatting as internal storage. DO NOT do this - the 32gb of internal, faster storage is a much better place to run apps from, not the SD card even though it is A2 "app-friendly" classified. All CONTENT will automatically go to the SD card in the future, such as downloaded Netflix and Prime Videos.Pay attention to the following issues which might develop:1. Simultaneously downloading videos or other content AND watching a previously stored video. This can tax the memory controller in the SD card since essentially the device is attempting to read your video and write your downloading episodes at the same time (subject to buffering). It shouldn't be a problem,but it might. I usually download content when I'm not using the tablet.2. Moving lots of content from external storage - like a thumb drive - to internal storage. The process is ALWAYS a lot faster going from USB 3 thumbdrives to internal factory storage, and slower when writing to the SD card.In my review title I mentioned I prefer Samsung. Without doubt they make more dependable SD cards that more consistently "hit" their specs and don't throttle down as much on large file transfers. However, Sandisk pretty much "owns" the A1 and A2 "app friendly" micro SD space, and they frequently go on sale. Since they no longer "corrupt" large file transfers (I'm talking about moving a 30gb music collection to an SD card in a computer, not just a couple of gb), I no longer avoid Sandisk like the plague. Still, as they say, once burned twice wary.I'm hunting for reviews from Raspberry Pi users. Running an actual operating system from a micro SD card is equally hard, or harder, than running Android apps. So far, the micro SD cards recommend for those Raspberry Pi systems are NOT A1 or A2 class or even necessarily "faster" micro SD cards - apparently speed on larger files doesn't necessarily correlate to the speed required for smaller, constant file transfers that an operating system needs.It's good to see micro SD card prices become so low and commodity-like. I can remember when cards were a dollar a gigabyte, or much more. For under $20 I'm more than willing to give this Sandisk A2 128gb micro SD card a workout in my Fire HD 10 9th gen.I'm also a little surprised to see all the new brand names. I'm used more to Samsung and Sandisk at the top, with Kensington, Patriot, etc. as the next tier. My guess is Chinese subcontractor factories feel less bound to have a long-standing brand name and are just going direct to market. Time will tell how this works out for consumers.