Enterprise PCIe flash pioneer Fusion-io began the trend by acquiring IO Turbine last August, and OCZ picked up Sanrad for its PCIe caching software in January. Solid-state vendor STEC internally developed its EnhanceIO caching software, and EMC’s caching software and FAST auto-tiering appliance play a big role in its VFCache server-side flash product.

The acquisition of FlashSoft leaves startups Nevex, Velobit and perhaps a few other vendors still in stealth as obvious targets for solid-state vendors. Nevex and Texas Memory Systems last week said they were jointly developing software that would speed applications running on TMS SSD storage.

FlashSoft software turns SSD and PCIe sever flash into a cache for the most frequently accessed data. The company came out of stealth last June with FlashSoft SE for Windows and later added FlashSoft SE versions for Linux, VMware vSphere and Microsoft Hyper-V.

SanDisk said it will sell FlashSoft SE as standalone software and with the Lightning Enterprise SSDs and upcoming PCIe-based devices based on technology that it acquired by buying Pliant last May for $327 million. SanDisk’s SSDs are used by Dell EqualLogic, NetApp, Hewlett-Packard and others through OEM deals.

“We think this is the next step in our performance acceleration journey,” said Greg Goelz, VP of SanDisk’s enterprise storage solutions group.

Goelz said FlashSoft software was appealing because it can work with any hardware and that fits with SanDisk’s OEM model, and it scales better than competitors. “We looked at how did they scale in capacity? If you move from 100 gigabytes of SSDs to terabytes, does the metadata scale exponentially? Is the overhead low? Does it have the best approach to support what’s out there today and to support the evolution from single server to virtualization and clusters? FlashSoft was well ahead of anybody in the market by a substantial lead.”

SanDisk did not disclose the purchase price for FlashSoft.

FlashSoft today said FlashSoft SE 2 is in beta, with support for Linux, larger solid-state drives (SSDs) and read-only cache. FlashSoft SE improves application performance with solid-state storage by turning SSD and PCI Express (PCIe) server flash into a cache for the most frequently accessed data.

FlashSoft developers have been busy. CEO Ted Sanford claims 800 feature enhancements in version 2. Besides Linux support, the biggest improvements are an increase in the maximum cache from 256 GB to 1 TB (it now can accelerate up to 10 TB of active data), and the ability to detect a failing SSD, issue an alert, and switch the cache to pass-through mode to avoid writing data to any SSD without a redundant backup. FlashSoft SE 2 also has a new GUI that provides runtime data and statistics through the Windows Management Interface (WMI) API.

The software now supports read-only caching as well as read-write caching. Sanford said read-write caching works best for most applications, but apps with large read requirements such as video can benefit from read-only. FlashSoft also increased its read cache performance for large files and data sets.

In addition, FlashSoft upgraded FlashSoft SE-V for virtual servers to 2.0, adding support for virtual servers running on Linux and Windows.

FlashSoft SE pricing starts at $2,000 and depends on the number of servers accelerated and the type of SSDs used. FlashSoft sells FlashSoft SE as standalone software, but Sanford said he is working on partnerships to bundle the software with SSDs.

Sanford said the new features were mostly suggestions from early customers and organizations evaluating FlashSoft SE software. FlashSoft is probably also hearing footsteps from other flash cache competitors entering the market.

EMC‘s PCIe server-side cache “Project Lightning” product that uses EMC’s FAST software to improve performance is due out by the end of the year, as is Fusion-io’s ioCache that uses software that Fusion-io acquired from early FlashSoft competitor IO Turbine. SSD vendor STEC is sampling its EnhanceIO SSD Cache Software to partners and early customers, startup VeloBit is in beta with its SSD caching software, and Nevex and perhaps other startups are on the way with  competing products.

“We feel like it’s a significant accomplishment that we’re shipping a 2.0 release in advance of anybody else shipping 1.0,” Sanford said. “We believe we will continue to advance the art. Leveraging flash as cache in existing servers or being added to new servers coming out is a large market. When you can improve an application’s performance by three to five times, that’s a fundamentally strong value proposition. There will be room for significant success for several companies.”