This afternoon, Seagate Technology made an unexpected announcement coming so soon after the Storage Visions conference in Las Vegas – a tag-along with CES. The company’s second wave of Savvio hard drives in the 2.5" form factor will be revved up from 10,000 to 15,000 revolutions per minute.

But as an indication that such revolutionary speed, literally speaking, may not yet be cool enough for notebooks where the company’s Momentus product line revs up to 7200 rpm, the 15K series is being billed for use in RAID storage batteries for the enterprise. There, Seagate says the new Savvios will run cooler than a typical datacenter installation, drawing 40% less power per drive while consuming about a third of the rack space.

The company is already calling the 15K editions “the world’s fastest hard drive” at 36 GB and 73 GB capacities; the existing 10K.2 editions support 146 GB capacity. It’s citing HP as having independently proven that claim, though just yet, we’re not being given raw numbers.

But here’s an idea of the proportions Seagate is shooting for: Today’s 500 GB Barracuda SATA drives in the conventional 3.5" form factor have sustained transfer rates of about 49 MB/sec, and maximum rates of nearly 62 MB/sec. Seagate has already tested its Savvio 10K.2s at transfer rates as high as 89 MB/sec, which brings the expected mean sustained rate closer to about 70 MB/sec.

Now, multiply the rotation rate by 1.5, and you have reason to expect the sustained rate for the 10K.2s to break the 90 MB/sec. mark, and perhaps eclipse the 100 MB/sec. mark for brief intervals. This is at a time while Maxtor FireWire external drives perform at about 38 MB/sec.

But it remains to be seen whether enterprises buy into the argument that the more reliable each drive unit is, the fewer you need in each RAID array. Conceivably, all that recouped storage bay space could be quickly consumed with more Savvios.

Seagate has recently been retooling its marketing plan, by moving the Maxtor brand it acquired – which the company had been planning to simply scuttle – into the high-capacity mainstream, while gearing the classic Seagate brand for high-performance applications and the enterprise.