On SD and MicroSD cards

Last updated on 2024-07-22.

I think SD cards are the best general-purpose data storage tech currently being made. Why?

• Widely available and widely used.
• Reliable enough, especially when you buy "industrial" cards made with SLC flash (one of many, many examples of older tech being better). These are available from electronics suppliers like Digikey.
• Fast enough transfer speeds.
• Cheap. Even industrial-grade SD cards are cheap enough.
• Tiny, easy to store and conceal.
• Easy to destroy. You can put a MicroSD card in a paper shredder.
• Unlike USB devices, an SD card cannot do arbitrary things to your computer. You do not have to trust the card; you need only trust your card reader.

They have some downsides:

• MicroSD cards are too small, to the point that they are difficult to handle, especially for people with certain disabilities. Standard size SD cards are more than small enough.
• They are also too small to label. You can barely write a single word on a full-size SD card. MicroSD, forget it. I label my MicroSD cards by putting each one in a small plastic "pill bag" and putting a label on the bag.
• They are not dumb enough. Each one contains a microcontroller -- that is, a CPU. I have no idea what that little CPU is doing. But at least it cannot take over or fry my computer when I plug it in. (Don't use USB flash drives.)
• NAND flash is still less reliable than magnetic or optical media.
• SD cards have a write-protect switch, but it's lame, it just tells the drive "please don't write to me", and the drive may ignore this.

Even with the downsides, I find SD cards to be the best option for my storage needs. I use them for everything -- that is, when I am not using paper, the king of data storage, which beats them all just because it can be accessed without a computer. SD cards are the closest thing to being today's floppy disk, and I mean that with great respect.

Other good (but not as good) storage media:

• Floppy disks, if only someone could make one that can handle the disgusting bloat of today's software. (Bring back "Zip" disks?)
• Optical discs. Called "obsolete" today because they hold "only" hundreds of megabytes. Sad.
• Tapes. Reliable high-capacity dumb storage that has been deemed "enterprise" and therefore expensive. Also I don't really need to store 999 TB of data.
• Even audio cassette tapes would be good if they weren't so agonizingly slow and low-capacity.
• CompactFlash. Too bad it has been relegated to being an overpriced specialty medium now, basically only used in cameras. The tech is better than that in SD cards.

Inferior storage:

• Hard disks. They can store a lot of data -- multiple TB nowadays. But who really needs that much data? No one.
• SSDs. Basically bloated huge overcomplicated SD cards. I know they are much faster than SD cards, I don't care, I don't have that much data, and I typically keep all working data in RAM anyway.
• USB flash drives. Admittedly useful for "sneakernet" data transfers, but, then, so are SD cards and card readers.
• The "cloud". Worst of all.

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