Exabyte's new VXA-172 tape drive can become a VXA-320 with double the capacity through a firmware upgrade. The feature is called capacity-on-demand and is possible because the tape drive engine is the same for the VXA-172 and VXA-320.

The current VXA 2 drive offers 80GB raw capacity which it writes at 6MB/s. The VXA-172 provides 86GB, written at 12MB/s and uses the same tape media as the VXA-320 drive which has 160GB raw capacity, also written at 12MB/sec.

The VXA-172 effectively replaces the VXA 2 offering an extra 6GB capacity and twice the I/O speed. However there is no upgrade from the VXA 2 to the VXA-172. Chris Wening, Exabyte's international sales director, sees VXA 2 customers going to the VXA-320 as it offers twice their current capacity.

The VXA-172 can be upgraded via a firmware revision to the VXA-320. The new firmware results in the data packets on the helical-format VXA tape being half the length of the VXA-172 packets. Asked whether other tape drive manufacturers should offer firmware-based capacity upgrades, Wening said: "In a New York minute."

In theory tape manufacturers could take a fast, high-capacity drive and reduce its capacity and speed to that of the previous generation. For example, an LTO3 drive could be reduced to LTO2 capacity and speed and then an upgrade, via firmware, offered to LTO3 performance level. In the light of the Exabyte move it seems an obvious thing to do, but does require the ability to reduce a tape drive's performance by firmware.

The VXA-172 Packet Drive is available now, priced from £400 and the firmware upgrade, costing £199, will be available in the second quarter of this year. An autoloader, the VXA-172 Packet Loader, offering ten cartridges and one drive, is also available. VXA-172 tape media is available in either 40GB or 86GB (raw) capacity versions for £8.00 and £16.00 respectively.

Exabyte is targeting the VXA-172 drive at the DAT72/DDS-4 upgrade and replacement market, but not the Travan replacement market. Wening said: "That's effectively a DVD market now."