There is a lot that can affect noise levels. Lower-power chips, for one, can reduce energy needs and cooling requirements. But working against low-power chips is a trend toward putting more of them in compact systems: A 5-kilowatt rack might get replaced with a 20-kilowatt rack as part of a server consolidation.

The level of attention paid to noise reduction by manufacturers can vary. Some vendors put acoustic mufflers on their racks, although these racks may cost more. And equipment can be designed to reduce noise, but that manufacturing priority depends on the customer.

Although vendors are aware of noise issue, buyers aren't pressing them to make it an important consideration in design, said Don Beaty, a consulting engineer. Beaty has headed the American Society of Heating, Refrigerating and Air-Conditioning Engineers's Technical Committee TC 9.9 for mission-critical facilities, technology spaces, and electronic equipment.

"If (users) are not pushing back on the manufacturers, why would the manufacturers spend the money or make that a main criterion?" said Beaty, referring to noise levels. "They are applying their own value system instead of their customers.'"

More vendor focus on the issue would lead to improvements, said Beaty. "A base design would include more noise mitigation."

But vendors would also be concerned about whether noise mitigation increases power needs, or whether things like acoustic doors make equipment harder to work on, he said.

Wade Vinson, a thermal strategist at Hewlett-Packard, said datacenters are up against regulatory limits on the amount of noise they can generate, forcing datacenter managers to put in hearing protection programs. "In many ways, servers being quieter can be a competitive advantage for some companies," he said.

Vinson also noted that trying to keep fan power down -- by using aerodynamic fans with variable speed controls that adjust to server load -- can reduce total power use, a major consideration of IT managers. "We have a big incentive to keep fan noise down and that's to save power," he said.

As users upgrade to larger servers, and bring more power and air conditioning into their datacenters, "...for the first time they are going to start to be more cognizant of the noise levels as they try to increase the density of equipment," said Vinson.

Robert Rosen, a CIO at one of the agencies that makes up the National Institutes of Health in Bethesda, Md., and past president of the IBM user group SHARE, recalls working with large VAX servers that were so loud "we couldn't even think in that room." Today, he has installed special carpeting in his server room that prevents static electricity and reduces sound levels. If vendors make noise reduction a consideration, that would be a good move, he said. But Rosen said he won't sacrifice system performance for airflow improvements.