The title might seem a little harsh, but it is a direct quote from the video by [Linus Tech Tips] that you can see below. He picked up a board that is a RAID 0 controller for up to ten SD cards so you can use them as a conventional SATA SSD. Of course, the channel’s tag line is “impractical solutions for improbable problems” but even by his own admission, this is pretty impractical.
It is odd for us to scoff at any kind of hack, but honestly, it is hard to see the value to this, other than it is amusing to think some factory turned these boards out hoping to make a profit. Besides being amusing, though, it is also a good exercise in design trades. For example, when you design a car, you want it to be safe, but you can’t make the body out of four-inch thick steel because of cost, weight, and fuel consumption. So you balance these concerns by making tradeoffs.
The trades here are mostly one-sided. SD cards are cheap, we suppose, although the cost of a proper SSD isn’t that much these days, either. SD cards are relatively slow, the RAID 0 controller helps with that — at least, it should. Of course, the downside is now if any of the ten cards fail, you’ve failed the whole array since RAID 0 has no redundancy. Also, although the sequential data performance was adequate, [Linus] measured the random performance and it was abysmal. We can’t tell if that’s inherent in the design or just a flaw in the execution.
Generously, let’s say you pay $40 each for 128 GB SD cards, that’s $400. You can easily get a 1TB SSD for about the same cost. [Linus] couldn’t figure out why these boards were made, and neither can we. Maybe someone will have an idea in the comments.
Now, if you hacked the board to not use the RAID controller and just used it as a carrier for ten SD cards it would be great for a data logger. Maybe if you were building a custom laptop and wanted it to be somewhat Rube Goldbergesque, this could be a good start.