US supplier Gear6 has announced network-attached storage (NAS) boxes featuring a transparent RAM cache.

Gear6's CACHEfx is a RAM cache, using standard computer memory, packaged as a set of appliance building blocks, 250 or 500GB in size, each with a processor and Reflex operating system. Up to ten of these building blocks are stacked together in an active:active cluster formation and virtualised into a single memory pool of up to 5TB by the OS. This also uses the individual I/O ports in parallel to scale from 250,000 to 2.5 million IOPS.

The appliance sits on a Gigabit Ethernet link between network-attached storage (NAS) and accessing servers. No changes are needed to the NAS or the accessing servers. Frequently-accessed files in the NAS array are stored in the cache and accessed much faster than from disk. The CACHEfx has a latency of less than 500 microseconds, and can handle more I/Os per second, 250,000 plus compared to a hard drive's 250-270. It can also deliver better throughput than a hard drive.

Texas Memory Systems has its RamSan, a RAM-based solid state disk (SSD) product which peaks at 400,000 IOPS. It is presented to accessing servers as a block-level hard drive array and is not transparent to them as the CACHEfx is.

Attorn is another RAM-based SSD supplier. The Attorn, TMS and Gear6 products are all faster than flash memory-based SSDs.

The target market areas for Gear6 are I/O-bound NAS applications needing higher IOPS capacity and throughput for terabyte-level datasets. A Sony subsidiary is using Gear6 technology to speed up movie special effects rendering time.

A base CACHEfx unit with 250GB of RAM costs $400,000 (about £200,000). Gear6 says software can be downloaded from here to estimate how much a customer's NAS performance might be boosted.