Dec 8, 2006 - Processor Magazine: Server Quietization

eRacks Press

Processor Magazine, Online:
December 8, 2006
Vol.28 Issue 49
Page(s) 25 in print issue

Server Quietization
Reducing The Hum Of Servers Without Sacrificing Quality

The hum of a server is a sign of two things: that there’s a tremendous amount of power inside the enclosure, and that the fans are working overtime to make sure there are no excessive heat problems, which can cause crashes—or worse. Yet for anyone who works in a smaller data center or even keeps a row of servers close at hand in an office cubicle, server hum can be distracting and make it hard to hear when talking on the phone, for instance. Not every data center is situated in a server room where you can occasionally check on system status and run admin utilities. Instead, you might have a server right under your desk.

Quiet Down!

Server quietization is one of the key issues for small to midsized enterprises, a problem that a larger enterprise rarely needs to address. For the most part, the issue has become more noticeable as power output has increased and data centers rely on more and more servers to run the business. Server manufacturers use several methods to make servers operate as quietly as possible.

Fan placement, low-decibel fans, heatpipes, watercooling, and optimized airflow inside the chassis can all help reduce noise. Fanless systems, which are much more expensive and use an array of heatsinks, heatpipes, and other cooling methods, also provide an innovative approach.

“Small to medium-sized companies tend to utilize tower-based platforms that are often colocated with employees, so noise levels can greatly affect productivity in these environments,” says Christina Tiner, group manager of Industry Standard Server product marketing at HP ( “Mechanical designs of the servers greatly impact acoustics. Fan location and airflow patterns determine the amount of air required to cool the system.”

“The latest trend is to make sure that the air path from the front of the system to the processor is as clear as possible,” adds Ken Haugen, the director of server engineering at Gateway Computers ( “Any active component other than a fan in that air path will preheat or slow down the air path, forcing the fan to run faster to keep the processor cool and make more noise. Other trends in keeping servers quiet include counter-rotating fans, thicker and slower fans, and larger processor heatsinks. Finally, the latest-generation processors use much less power than previous generations, which decreases the thermal load and allows the system to run quieter. Some manufacturers also use liquid cooling, but this adds too much cost for most applications and is less reliable.”

Haugen notes that companies that situate servers near employees should look for server manufacturers that design quiet servers, relying on low-decibel fans and highly optimized CPUs that are designed for whisper-quiet operation. He notes that some server rack manufacturers have designed cabinets that use sound-dampening techniques, but the heat output and power drain for these cabinets sometimes negates their value.

The Marketplace For Quiet Servers

One company that specializes in quiet servers is eRacks Open Source Systems (, which offers products designed for smaller companies that may not have a server room. There are two main product offerings for low-decibel servers: those with a fanless design that are fully silent and those that are quietized with optimally placed, low-noise fans.

“Placement and location of internal fans is key, and we select and specify only certain chassis designs which meet our criteria for fan placement and location to avoid or minimize auditory noise leakage from the chassis,” says Joseph J. Wolff, eRacks’ CTO and founder. “We also use only the best available noncontact fan technology, and at the lowest fan RPMs possible, to drastically reduce the noise produced by each individual fan, usually to about 1/10 of the original decibel level output.”

Nixsys ( is another company that has received customer requests for fanless and low-noise servers. Nicolas Szczedrin, a Nixsys spokesperson, says the requests sometimes come from small multimedia companies and recording studios that require servers with high processing power, yet the companies don’t want to disrupt any of their daily activities. He says one partial solution is to use a chassis for a server that can automatically regulate fans for low-decibel operation, but he says the trade-off is in the extra heat buildup.

“We have had more acceptance with quiet fans because they are very quiet, and if they are well-designed and tested properly, you can use a very large range of processors and components, making the systems more powerful, easy to upgrade, and lower cost,” Szczedrin says.

Shuttle ( also makes systems that operate at low decibels and can be used as servers. Its XPC-SB83G2B system uses a silent power supply, an “integrated cooling engine” to manage airflow, and fans that change their speed depending on the processor requirements. Shuttle systems have the added advantage for smaller companies in that the chassis is remarkably small.

Server Or Rack Issue?

Most server manufacturers agree that quietization is mostly a server issue, not a rack issue. If the server itself is noisy, sound-dampening racks typically just obstruct airflow. Some companies, such as NEC ( and eRacks, do have rackmountable servers that use liquid cooling, so they operate in near silence. These liquid-cooled, rackmount servers are typically more expensive but operate at the lowest decibels possible.

According to eRacks’ Wolff, “We can centralize the pump, tank, and cooling infrastructure for a rack of multiple servers using manifold technology.”

In the end, running a quiet server has many benefits for smaller companies. It means a server room is less of a requirement down the road, and admins can keep systems in the same office and have easy access to server utilities and monitoring software.

by John Brandon