Wow. That's almost exactly what I was looking for last week.
I have an old machine I'd like to turn into a WORM server, but I want it to be silent and would rather re-use a bunch of old memory cards than spend money on new storage.
All I could find was a device that put two MicrSD cards into a single SD card. This is even better.
I'd buy it if there was a USB version, since the computer I want to re-use only has USB ports.
Not just performance. Reliability and data loss are also bad. All of these adapters do raid-0, which means any one card failure (very common, I have seen it a lot in my personal devices) will damage the volume.
As I have a lot of odd SD cards unused in drawers I would be more interested in these adapters if they exposed every card as its own drive so I could do ZFS, or if they did "real" raid.
I was thinking it would be cool as a small NAS with a mirror. I want to put my movies and photos on it, and having a huge mirror is very useful for that type of workload. I could drive it with a cheap ARM device, which should allow me to stream a 4k video over the network, provided my network is the bottleneck.
Why not just use an actual 2.5" SSD instead of a bunch of SD cards in a terrible quality adapter?
At least with the SSD, you only have one microcontroller doing god-knows-what to hide the horrific reality of flash storage, vs 10 SD card microcontrollers and one on the adapter board, which are all probably even worse.
I'd be wary of this unless you're planning on multiple levels of redundancy. Those old cards (at least the ones I've collected from phones over the years) are just so poor that you can't rely on them for much.
WORM is a slightly less scary, but I still wouldn't trust them without being able to handle failure of 50% of the cards.
There are extremely tiny and cheap micro sd card USB adapters, basically just the size of the card. Stay away from generic ones though. Lexar and SanDisk make good USB 3 compatible ones, and are quite reliable.
Don't get Kingston, like this one, they seem to break leaving half the thing inside the USB port way too often in my experience :
My experience with SanDisk has been mediocre. I've multiple microSD card failures in GoPros and RaspberryPis. Their microSD to SD adapters are the absolute worst and their cards, an only theirs, will continuously dismount and remount every 30 seconds or so if left idle in my laptop.
Sony has let me down as well, their cards have either poor or no wear leveling and will die in a matter of weeks when used in a GoPro. Every single one I bought has died inside of a year.
The longest lived microSD card I currently have is from Lexar and I recently bought some Samsung cards to see how they'll do.
The better-known brands like Sandisk and Sony have a ton of counterfeit clones in circulation. Some of the problems you are experiencing might well be due to that.
Lexar is a less-known brand, less likely to be used by counterfeiters.
My personal record is an 11 year old 1 GB Lexar that's even been thrown into the washing machine by mistake a couple times. Still in use. I find these things extremely resilient in general, no issues with SanDisk at all for me.
I refuse to buy SanDisk. Have had multiple microSD and USB flash drives from them that are permanently stuck as Read-Only. According to them, it is a common manufacturing error in their process.
Isn't that thing really really dangerous? It does use Raid 0 (ie, no redundancy) on one of the fastest wearing media out there. Unless I missed some recent development, SD cards are a lot more subject to wearing than SSD drives, therefore any use of them to build a disk with striping would be just crazy.
A 15TB 2.5" SSD (MZILT15THMLA) is ~$6000, or $12000 for the 30TB (MZILT30THMLA), both at $400/TB. 10 of these cards are $4500 for 10TB at $450/TB. If you pay that much on storage you'll probably want something that offers you more capacity, performance, and reliability then a multi-microSD setup.
[updated to correct pricing and calculation based on observation made by the fellow commenter below]
I'd never trust a single 15TB device though, so would need to consider the cost of multiples of them in my VFM calculations.
Then again even 1Tb devices make me nervous due to the amount of time it can take to rebuild your redundancy level after replacing iffy units, and might insist on straight mirrors (R10) rather than something more space efficient like R5 to try keep rebuild time down as low as possible.
I wonder what these are for ? Is it for devices with limited hardware (single 2.5" slot), or is it because it is sometimes the cheapest way to accelerate a system (hard to beleive) ?
