NComputing has sold more than 600,000 virtual desktops in the last three years, offering an innovative way to harness what it calls “the untapped power of existing PCs.”

The 5-year-old NComputing provides the software that creates a virtual desktop environment on any Windows- or Linux-based computer. The NComputing solution differs from competitors Citrix Systems, Microsoft and VMware by also including a client device that improves I/O through a patented process.

The client device is a flat, 4-inch square connected by wire to a server or commodity computer box. The software reconstructs the virtual desktop stored in the memory of the shared computer and transmits it down the communications link to the device on back of the monitor. (All the company’s products rely on cables at this time; a wireless version of the product is in the works, according to company officials.)

NComputing’s “secret sauce” device, which costs about $70, bolts to the back of a monitor, allowing that monitor/keyboard/mouse/speaker “station” to perform as if it had its own processor box beside it.

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A number of stations can run off one commodity desktop computer using this technology. NComputing has a display in its northern California headquarters that demonstrates 30 stations—each running applications including DVD video, streaming video, browsers, spreadsheets, word processors and other applications—working off one Dell 1.86GHz computer that cost less than $1,000.

There are two versions of the client device available: the X-series, which uses access terminals that connect the services directly to the desktop box or server, and the L-series (for LAN), which uses Ethernet connectivity featuring NComputing’s high-performance UXP (User eXtension Protocol).

The economics of this kind of system are compelling, especially for funds-challenged school districts.

A classroom computer lab with 20 to 30 seats needs only one processor. When applications have to be upgraded, only one license—instead of 20 or 30—must be bought. Maintenance costs also are cut way back.

Two factors set NComputing’s software/hardware product apart from standard thin clients, such as those marketed by Wyse and Sun Microsystems: Each NComputing station uses a mere 1 watt of power—as opposed to 85 to 150 watts per common desktop, and somewhat less for a typical thin client—and there is virtually no latency in the performance.

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“That’s exactly the reason I joined the company,” said NComputing CEO Stephen Dukker, who founded eMachines in the 1990s. “When I was first approached, I said to the founders, ‘The idea sounds great, but what about latency?’ That had always been the main problem area for thin clients—they just weren’t fast enough. You found yourself always waiting for the cursor to catch up with you.”

NComputing co-founders Young Song and Klaus Maier went back to the drawing board and returned to Dukker after improvements were made. It worked; Dukker was sold.

“[We acknowledge] the fact that even the lowest-end computer is now a supercomputer, and that the user is using maybe 10 percent of that capacity,” Dukker said. “We are the unexpected benefit of virtualization.”

NComputing recently scored what it claims is the largest single virtual desktop installation in the world—a 180,000-seat installation in schools in Macedonia in Eastern Europe. The company now has installations in 70 countries.