That's right. The cassette tape. It's back. IBM and Fujifilm are actively developing prototype data storage cassettes that can hold up to 35 terabytes apiece and are up to 200 times more efficient than traditional hard drives.
You can think of a data cassette like a traditional hard drive: storage is magnetic, except instead of platters that spin, you get a long piece of tape that runs back and forth. Since the tape winds up, you can fit a lot more storage into a much smaller space, and IBM's prototype 35-terabyte drives measure just 10 centimeters by 10 centimeters by 2 centimeters. Tiny.
These drives are being designed to be used in large data centers, which are currently maxing out on space using platter drives up to three terabytes in size. This isn't going to be enough for future big data projects like the square kilometer array, a huge radio telescope that will be producing one petabyte of data per day by 2024. Tape drives also have the advantage of being much more energy efficient: since the tapes aren't moving when they're not being read, they use about 200 times less energy than a data center full of constantly spinning magnetic platters.
For most consumers, tape drives won't be replacing traditional hard drives for day-to-day use, primarily because accessing data off of a tape takes significantly longer: if you just read something off of the start of the tape, and the next bit of data that you want is at the end of the tape, it has to physically spool all the way through in order to get there, which takes an unacceptably long time for most casual users. However, back when I was just a little whippersnapper, many desktop systems came equipped with tape drives pre-installed to be used for archiving and backup, and there's no reason why that's not a niche that they can still fill today.
Personally, I'd love to have a tape drive in my desktop that mirrored my entire HD once a week or something. I do that anyway with external HDs and network storage, but it's expensive, and since I never access any of it unless something goes wrong, access speed is not important. Obviously, tape drives aren't for everyone, but this next generation of massive and tiny drives might actually come in handy, even if they are a throwback to Well I'd put a cassette tape joke in here, but I'm not old enough to know any.
Via New Scientist