Ultrium tape drives are out-selling SDLT drives almost two to one, as shown by the format's 2:1 penetration versus the SDLT format based on the Gartner Dataquest, Tape Drive Review and Forecast June 2003*. According to Gartner, LTO tape drive shipments for the first nine months of 2003 are still outpacing SDLT shipments by nearly 2:1.

Also, based on a July 9, 2003 report by Gartner Dataquest titled "2003 Tape Automation Systems Forecasts," more than twice as many LTO tape libraries were shipped in large automation solutions in 2002 as compared to libraries based on DLT/SDLT.

The current LTO 2 has 200GB raw capacity and moves data at 20MB/sec. At first glance it is surprising that LTO claims its capacity is a reason for people to prefer it over SDLT since SDLT 600 offers 50 per cent more capacity and 50 per cent more I/O speed with 300GB native capacity and 32MB/sec transfer rate. However, the LTO group get to capacity points before Quantum.

LTO 2 has been competing with the inferior spec SDLT 320 which offers only 160 GB capacity and 16MB/sec transfer rate. The LTO consortium has managed to get the jump on Quantum and each SDLT generation is effectively late to market. There are no speed and capacity reasons why existing LTO customers should change to SDLT.

The LTO people say reliability is key to LTO's success. No doubt it's important but there are statistics showing that SDLT drives and media are any less reliable than LTO. The LTO people say that LTO is open, with three competing manufacturers, and this is important. Quantum has Tandberg as a second manufacturer of SDLT drives and claims better tape transferability between Tandberg and Quantum drives than that it says is possible between different manufacturer's LTO drives.

However, John Greenwood, Product Sales Manager for Oxford-based NCE, says, "Tandberg and Quantum don't compete with one another. Tandberg has Europe and Quantum North America. They have quite clearly assigned territories to each other." The intenser LTO supplier competition drives down prices.

LTO is more open than SDLT from this point of view. It also has a capacity edge on SDLT and its price/performance is claimed to be better too. Nick Powling, business development manager, north EMEA, for Certance, says, "LTO 2 drives are about £500 more than SDLT 320 ones. For that you get better price/performance. SDLT 320 will store 115 GB/hour but LTO 2 is 245 GB/hour. You get more than twice the speed and obviously you're getting more capacity." Greenwood agrees completely; "LTO has better price/performance than SDLT."

LTO 3 next year As shown in Techworld's RTFM section recently, the third LTO generation will arrive next year. It will have a 400GB native capacity and a raw transfer rate of 40-80MB/sec. Certance, one of the LTO consortium members, is bullish about being first to market early in 2004; March is suggested by Greenwood.

The SDLT 600 current product will then be left behind with Quantum needing to bring out its SDLT 1200 - 600GB raw capacity and up to 80MB/sec transfer rate - to catch up and overtake. Quantum says its SDLT 1200 will be released in 2004, with the follow-on SDLT 2400 coming in 2006 or so. LTO 4 could arrive earlier, 18-24 months after LTO 3. It's hard to see why customers should stop buying LTO drives at the rate they do.