“A company parking lot is just really cheap real estate,” Mr. Schwartz said.

Mr. Schwartz rose to the chief executive position less than six months ago with a mandate to reverse the decline Sun has experienced since the end of the dot-com boom. And computing experts suggested that the mobile data center was a gamble that could pay off.

“What an out-there idea,” said David A. Patterson, a computer scientist at the University of California, Berkeley, who has worked closely with Sun and with Mr. Hillis. “You could convert your warehouse into a modern data center.”

Mr. Schwartz said the mobile data center would be attractive to customers that need to expand computing capacity quickly. Sun will lease as well as sell the systems, and Mr. Schwartz said the entire system is recyclable.

On Monday, he gave a reporter a tour of the prototype system, which sits in a container case adjacent to a Sun office building here, connected to two large fire hoses for water cooling and 500 kilowatts of redundant power.

Painted black with a lime green Sun logo, the system can consist of up to seven tightly packed racks of 35 server computers based on either Sun’s Niagara Sparc processor or an Opteron chip from Advanced Micro Devices. The system includes sensors to detect tampering or movement and features a large red button to shut it down in an emergency. Once plugged in, it requires just five minutes to be ready to run applications.

Sun has applied for five patents on the design of the system, including a water-cooling technique that focuses chilled air directly on hot spots within individual computing servers.

The system, which Sun refers to as “cyclonic cooling,” makes it possible to create a data center that is five times as space-efficient as traditional data centers, and 10 percent to 15 percent more power-efficient, Mr. Schwartz said.