IBM scientists have set a new world record for data storage, cramming 330 terabytes of uncompressed data into a cartridge that fits into the world of your hand. That’s enough to fit three copies of every book ever written, while two of them could store every song ever recorded and released.

A total of 201 gigabits of data can be stored per square inch of the sputtered magnetic tape. The tape reels onto a cassette, which is deliciously old school, maxing out at 330TB on a single tape drive cartridge.

“Tape has traditionally been used for video archives, back-up files, replicas for disaster recovery and retention of information on premise, but the industry is also expanding to off-premise applications in the cloud,” said IBM’s Evangelos Eleftheriou. “While sputtered tape is expected to cost a little more to manufacture than current commercial tape, the potential for very high capacity will make the cost per terabyte very attractive, making this technology practical for cold storage in the cloud.”

I’ll try and don my scientist’s hat for a moment and get to the bottom of just how this magnetic tape works. It’s a mixture of several new technologies from IBM, utilising several thin layers of metal film that are coated with barium ferrite particles that are applied to the surface using a new vacuum technology. Barium ferrite is the same substance used on floppy disk tape drives and credit cards, and it’s making a comeback in a big way here.

While tape has often been seen as an unreliable method for storage, IBM, together with Sony, believe they’ve got it down pat with this prototype. It allows for a frankly ridiculous level of storage in tiny space, and could be an excellent solution for long-term storage or cloud drives. The current largest spinning platter hard drives (the traditional type you and I use) is 12TB, which is just 3.6% the size of this new tape drive. The downside to all this is that tape drives are markedly slower even than hard drives, and positively crawling compared to solid state storage. They’re also much more fragile, so they’ll need to be stored correctly. If they are safe though, magnetic tape has an excellent life span that far exceeds both hard drives and SSDs.

The potential of magnetic tape drives doesn’t end there either. IBM claims it’s going to be capable of doubling the storage capacity of these things every two years for the next decade. It’s conceivable that in 2027 we could have a tape in our hands that could store 10.5 petabytes of data, enough to hold both Grand Theft Auto V and The Elder Scrolls Online at the same time.