Less waste

It's no problem that flash costs more per-gigabyte, Fowler says, because customers typically use a high percentage of flash's storage space, whereas they often waste typical hard drive storage.

An enterprise building a large database application needs lots of speed in the form of Input/Output operations Per Second (IOPS).

"What you end up doing is buying a lot of disks because every one gives you another 300 IOPS," Fowler says. "But you're not necessarily filling the disks. You're taking a bunch of really fast 73-gigabyte disks but you may only put 20 gigabytes on each one. What you're doing is spreading out the IO rate across all the disks in order to get to thousands of IOPS. With flash you can get to thousands of IOPS on one device."

Moreover, flash "consumes one-fifth the power and is a hundred times faster [than rotating disk drives]," Fowler says. "The fact that it's not the same dollars per gigabyte is perfectly OK."

Neovest measured speed increases of tenfold and more over Serial Attached SCSI, while saving money on memory costs. "Most of the savings come from the reduction of system memory," Farmer says. "Normally these servers we're testing them on require 64 gigabytes of system memory. We can pretty much cut that in half, so we don't have to buy as large of a platform."

Solid-state technology, including flash memory, is certainly on the upswing, with IDC predicting 76 per cent annual shipment growth through 2012 in a market that generated nearly US$400 million in revenue in 2007. Fowler predicts that the majority of organizations building I/O-intensive applications will use some form of flash within a year.

But EMC notes that rotating disks aren't going to fall by the wayside any time soon. Currently, Fibre Channel storage is used primarily for high-performance applications, and Serial Advanced Technology Attachment (SATA) drives -- a less expensive alternative to Serial Attached SCSI -- are used when high capacity is the main need, Wambach says. Most data is accessed only rarely, so high-cost flash drives are usually unnecessary, he says.

"There is a relatively small percentage of capacity that can be justified on flash drives today," Wambach says. "What you'll see in the future is that Fibre Channel capacity is going to rapidly diminish as a percentage of overall capacity. You'll see SATA drives increase and you'll see Flash drives increase."

EMC has seen demand cut across a wide swath of use cases, including credit card transactions, financial markets and law enforcement agencies that need to do extremely fast searches. "What we found is that in almost any industry you look at, there are applications that are response time limited," Wambach says.

But some customers may be a bit too ambitious, and should carefully consider which applications really need the high speeds of flash, Fowler says. "Some people are asking us to do Oracle databases 100 per cent on flash," he says. "I'm a little skeptical myself. Most peoples' read and write activities don't need to be full bore on every piece of data."