When purchasing server processors directly from Intel, Google has insisted on a guarantee that the chips can operate at temperatures five degrees centigrade higher than their standard qualification, according to a former Google employee. This allowed the search giant to maintain higher temperatures within its data centers, the ex-employee says, and save millions of dollars each year in cooling costs.

If the chips failed prematurely at these higher temperatures, the former Googler says, Intel was obliged to replace them at no extra charge.

Intel denies this was ever the case. "This is NOT true," a company spokesman said in an email. Google declined to comment on its relationship with Intel. "Google invests heavily in technical facilities and has dozens of facilities around the world with many computers," reads a statement from the company. "However, we don't disclose details about our infrastructure or supplier relationships."

The ex-Google employee learned of this Intel pact a little more than a year ago, during a Google "Tech Talk" open to anyone at the company. The talk was given by a Google thermal dynamics engineer, part of a small team - perhaps no larger than two people - that oversees heat issues inside the company's data centers.

According to the same ex-employee, it is now the norm for Google to construct its data centers by piecing together intermodal shipping containers pre-packed with servers and cooling equipment. In 2003, Google filed for a patent on this sort of modular data center, and the patent was granted last October.

This modular setup - known internally as Project Will Power - allows Google to construct the building blocks for each data center at a central location and then ship them around the world as needed. Robert X Cringely first leaked word of Google's modular data center work in 2005, claiming the project began after representatives of the Internet Archive pitched the idea to Google co-founder Larry Page.

Heat Saves

It's no secret that Google builds its own data centers - and many of the servers within. It's long been said that after the top server vendors, the ad broker consumes more processors and hard disks than anyone else in the world - and Intel freely acknowledges that it provides at least some of the chips.

Intel also customizes power saving motherboards for Google - a service not afforded other customers. But our source tells us that any motherboard pact is separate from the companies' high temperature chip agreement.

If Google can leverage an extra five degrees centigrade from Intel, it can save a few penguins - and some serious cash. According to Data Center Knowledge, Google runs at least 36 data centers across the globe, and several more are under construction. One of the newer sites, in The Dalles, Oregon, includes three data center buildings, each measuring 68,680 square feet.

According to Mark Monroe, Sun Microsystems' director of sustainable computing, data center managers can save 4 per cent in energy costs for every degree (Fahrenheit) they raise the thermostat. If you run your data center at a higher temp, you use less power and spend less money on the equipment needed to cool it down.

But if you raise the thermostat, you may void your hardware warranties. "The hardware manufacturer will usually have a temperature range," says Rich Miller, editor of Data Center Knowledge. "If the equipment is running outside of the range, the manufacturer might be inclined to challenge any sort of returns or credits. That's the thinking across the industry."