The use of flash memory to dramatically improve transaction processing highlights a new line of storage appliances announced Monday by Sun.

See slideshow of Sun's Amber Road Storage 7000 series

The iSCSI storage appliances combine standard hard drives with flash memory and the latest AMD processors, with underlying software that optimizes performance by moving data around different tiers depending on changing needs. The Amber Road line of appliances includes entry-level, midrange and more expensive enterprise models.

Competitor "EMC has taken a conventional approach [in Symmetrix arrays] where they're essentially swapping out a hard disk drive for a solid state disk drive," says Burton Group analyst Gene Ruth. Sun is doing a better job leveraging the power of flash to improve transactional performance, he says.

"It's innovative because they're using solid state disk to enhance the performance of their back-end file system," Ruth says. (Compare storage products.)

Sun's ZFS file system is integrated into the appliances to manage up to four tiers of storage: DRAM, a read-optimized solid state disk, a write-optimized SSD and a general storage tier. ZFS automatically recognizes different I/O patterns and moves data around to make the best use of each tier, according to Sun. The key is to transparently manage and allocate storage space from flash, DRAM and hard disk in a highly scalable way, says Ray Austin, group manager of Sun's storage product marketing.

Early adopter Jason Williams, COO and CTO of hosted e-mail security provider DigiTar in Boise, Idaho, says using a solid state disk as cache, in combination with high capacity drives, makes sense.

"You need one [flash disk] to give you the performance, and you need a lot of storage behind it," he says.

Storage appears to be one of the few bright spots at Sun, which reported a loss of nearly $1.7 billion in its most recent fiscal quarter. Sun’s storage revenue grew 29% in the second quarter this year, a growth that Sun attributes to its "open storage" initiative that combines open source software with commodity hardware.

"Open source in storage is relatively new," says 451 Group analyst Jay Lyman. "There's some potential here. They have managed to grow that business."