Who says tape is dead?

December 2, 2010 – People have been predicting the termination of tape almost as long as they’ve been predicting the demise of mainframes. But both technologies keep hanging in there.

In the third quarter, tape media manufacturers pulled in almost $203 million in revenue, which is expected to actually increase slightly in the next quarter to $205 million, according to the Santa Clara Consulting Group (SCCG). And that’s just from tape cartridges; those figures don’t include revenue from tape drives and libraries.

All segments (formats) of the tape market are declining rapidly, with one exception: the LTO format.

LTO tape cartridges accounted for more than 86% ($175 million) of total cartridge shipments in the third quarter, or 6.2 million units, according to SCCG. Sales of LTO-5 (the latest generation, introduced early this year) cartridges were up 100% in Q3 vs. Q2, and accounted for 5% of unit shipments and 15% of revenues. LTO-4 cartridges accounted for 48% of unit shipments and 46% of the total LTO revenues. Even the LTO-3 segment grew in the third quarter (up 3%).

One reason that users stick with tape is that it’s still way cheaper than disk. Those LTO-5 cartridges cost only four cents per GB (assuming 2:1 compression).

According to a study conducted by The Clipper Group research and consulting firm, the cost ratio of storing 1TB of data on SATA disk vs. LTO-4 tape is 23:1. Even if you compare the costs of archiving data on a VTL with data deduplication vs. tape, the cost ratio is 5:1, according to the Clipper Group study.

And for the energy-conscious: Tape is 290X less expensive than disk in terms of energy costs. (The Clipper Group study was conducted two years ago, but with cost reductions in both disk and tape those ratios are probably still accurate.)

Sure, accessing data from tape is painfully slow, but successive generations of LTO have typically doubled the transfer rate. (Exception: LTO-5 only provided a nominal increase in transfer rate vs. LTO-4 – 280MBps vs. 240MBps – but LTO-6 is expected to almost double the transfer rate to 525MBps. That assumes 2.5:1 compression, vs. today’s average compression ratio of 2:1, which will come from the use of larger compression history buffers, according to Bruce Master, an LTO Program representative and senior program manager of tape storage systems at IBM.

And LTO-6 will boost native cartridge capacity to 3.2TB, or 8TB in compressed mode.

The LTO Program vendors (HP, IBM and Quantum) claim that more than 3.3 million LTO tape drives, and more than 150 million LTO cartridges, have been shipped.

In addition to the usual capacity and speed improvements, LTO-5 includes some nifty features such as media partitioning (which enables users to create two partitions on the cartridge, one for content and one for an index) and the Linear Tape File System (which is a free download that leverages dual partitioning and provides file system access at the operating system level).

The LTO Program celebrated its 10th anniversary last month.