Magnetic tape is back: Fujifilm to make 5x more LTO tape for AI

What is LTO tape?

LTO (Linear Tape-Open) is the modern data tape format. The principle is a cousin of VHS and audio cassettes: information is written as magnetic states on a layer of particles bonded to a very long tape. Fujifilm, which has worked with magnetic tape since 1954 and says it holds the largest share of the world market, launched LTO Ultrium 10 in 2025 with very fine hybrid magnetic particles. Since January 2026 it has sold a version that reaches 40 terabytes uncompressed.

Why does AI need tape?

Training and running large models means piling up enormous amounts of data. Keeping all of it on hard drives means keeping many machines powered and cooled, because drives draw electricity continuously, according to tape library maker Spectra Logic. A cartridge can be pulled out once written and parked in an automated library, where it needs no power to keep the data.

Fujifilm also argues tape is cheap for large volumes kept a long time. And a cartridge physically separated from the network creates an "air gap", which the company says helps protect data from threats such as ransomware.

The old rewind problem

Tape still has the flaw anyone who used a VHS remembers. It is sequential: to reach a piece of data, the tape has to run to the spot where it was recorded. A hard drive reaches files in milliseconds. So nobody will run Windows or open daily documents from a cartridge. For data you keep for years and rarely read, though, it fits.

VHS is not coming back. But AI has ended up leaning on a format with decades behind it.