The 60th anniversary of IBM's digital tape is coming up in May. Oh yeah, and tape is dead. Or so industry pundits have declared, echoing similar prognostications for the mainframe.

But in reality, tape has a long life ahead of it. At 60, in many ways, it's just getting started.

That's because, unlike the mainframe, tape's role in the enterprise is dramatically changing. Only a few years ago, with the emergence of cheap, high-capacity disk drives, many pundits thought tape would be relegated to the dusty storerooms of long-term data archive. Gone were the days when tape was used for primary backup and recovery or streaming media.

But, with the performance of next-generation tape drives hitting 525MB/sec. -- and at a price of around $25 per terabyte of capacity -- tape is too fast and too cheap to write off. New open file formats are also making it possible to use tape in new markets.

IBM's first magnetic tape device for digital storage, the 7-track tape, was introduced in 1952. The IBM 726 tape was about the size of a pizza and held 2.3MB of data with a transfer rate of about 7.5KB/sec. That's about enough to store a minute and a half of a song on your smartphone.

IBM arrived in the tape market a year after the first magnetic tape was introduced. It was used to store data from the Eckert-Mauchly UNIVAC I, the enormous piece of equipment that was the first commercial computer in the U.S. That tape reel held just 224KB of data.

IBM's 726 tape unit was released in 1952. Each tape held 2.3MB of data.

Tape rules the wallet

Today, an 800GB LTO-4 tape cartridge (1.6TB with compressed data) sells for as little as $22. In comparison, the lowest price of a 1TB 7200-rpm, 3.5-in. SATA hard drive is about $104 and a 1TB 2.5-in. hard drive costs about $128 on the low end.

So it's easy to see that tape cartridges sell for roughly one-fifth the cost of spinning disk. Multiply that by thousands of tapes and petabytes or exabytes of corporate legacy data, and the cost savings can be monumental.

Any cost comparison also has to take into account the fact that an enterprise might need just one tape library for backup and archive. That compares with the expense of running rack upon rack of spinning disk storage arrays.

The Ultrium Linear Tape Open (LTO) specification, by far the most widely used tape spec in the industry, has a road map that takes tape out to 32TB per cartridge and up to 1.2GB/sec. throughput. "We've done a public demonstration of 29.5Gbits of data in a square inch of tape," said Brian Truskowski, IBM's general manager of system storage and networking. "We see a lot of headroom in terms of areal density."