The biggest obstacle facing data centers when it comes to energy efficiency is how to keep the servers cool. Cooling systems for servers can be the biggest energy hogs of a data center, so most large companies are coming up with low-energy or even energy-free ways to keep them cool. Some utilize the outside air in cool climates, some run cool seawater through pipes near the servers, while others just let them run hot to avoid the high energy costs. Tech giant Intel has come up with one of the more novel approaches we've heard of: submerging servers in a mineral oil bath.
Over the past year, Intel has carried out an experiment at its Rio Rancho facility in New Mexico to see if a mineral oil cooling system built by Green Revolution Cooling would work to keep its servers cool with less energy and without harming the servers themselves.
Seven servers were placed in large vats of mineral oil and stood up on end, with the oil circulating through the servers to remove heat. They were compared for a year with seven other servers that had air cooling, with the same workloads running through both batches.
Intel found that it needed only 2 to 3 percent more energy to cool them on top of the energy needed to run them, instead of the 60 percent additional energy that's typically required for air-cooling servers. At the end of the yearlong experiment, the company took the servers apart and conducted failure analysis. The oil did not damage the servers or cause any problem.
Not only did the oil not affect the servers in a bad way, but because the system is able to keep them at such a constant temperture, it could actually boost performance and reliability.
Not much is needed to prepare servers for the oil bath -- just taking out the fan, sealing up the hard drive and removing the conductive grease between the server’s processor and its heat sink -- and even better, this type of system is suitable for data centers in any climate and it's a relatively cheap cooling option too.
“There’s no need for chillers; there’s no need for raised floors,” Green Revolution’s director of marketing David Banys told Wired. “You can put our servers in a barn that’s 110 degrees.”
Server company SuperMicro is getting ready to start shipping ready-for-oil servers for data centers that install the oil cooling systems.
The only real downside is when any submerged server needs maintenance, the oil has to be drained and it can be a little messy, but otherwise it seems to be an ideal solution.
You can see the CarnotJet cooling system in action in the video below.