Correction Appended

When Google was a graduate-school project being run from a Silicon Valley garage, its founders, Larry Page and Sergey Brin, built their own computers out of cheap parts meant for personal computers. They wanted to save money, and they felt that they could design a network of computers that would search the Web more efficiently than those available from traditional manufacturers.

Google no longer needs to pinch pennies. It is a solid member of the Fortune 500 with $9 billion in cash. Still, it is stubbornly sticking to its do-it-yourself approach to technology. Even as it spends more than $1.5 billion this year on operations centers and technology, most of the hundreds of thousands of servers it will deploy are being custom-made based on Google's own eccentric designs.

To be closer to its users and speed response time, it is building a worldwide string of data centers, including a huge site in The Dalles, Ore., with technologies it designed to reduce its ravenous need for electricity. These computers in turn use software developed with advanced tools that Google also designed itself. There are signs that Google is even preparing to create its own custom microchips.

"Google is as much about infrastructure as it is about the search engine," said Martin Reynolds, an analyst with the Gartner Group. "They are building an enormous computing resource on a scale that is almost unimaginable." He said he believed that Google was the world's fourth-largest maker of computer servers, after Dell, Hewlett-Packard and I.B.M.