[Beowulf] Servers Too Hot? Intel Recommends a Luxurious Oil Bath

Eugen Leitl eugen at leitl.org
Mon Sep 3 02:14:07 PDT 2012


Servers Too Hot? Intel Recommends a Luxurious Oil Bath

    By Robert McMillan 08.31.12 4:51 PM

You want to know a fast way to cool down a computer? Dunk it in a big tank of
mineral oil.

That’s a technique that Intel has been testing out over the past year,
running servers in little oil-filled boxes built by an Austin, Texas, company
called Green Revolution Cooling. As Gigaom reported on Friday, it turns out
that once you take out the PC’s fans and seal up the hard drives, oil-cooling
a server works out pretty well.

In its tests, Green Revolution’s CarnotJet cooling system used a lot less
energy than their air-cooled counterparts, Dr. Mike Patterson, a power and
thermal engineer with Intel, tells Wired. Intel found that oil-cooled systems
only needed another 2 or 3 percent of their power for cooling. That’s far
less than your typical server, which has a 50 or 60 percent overhead. The
world’s most efficient data centers — those run by Google or Facebook, for
example — can get that number down to 10 or 20 percent.

Intel’s research is part of a much larger effort to significantly reduce
power consumption in the data center. Power is one of the most costly aspects
of data center operation, particularly if you’re running the sort of massive
computing facilities that underpin web services as popular as Google or

Although it’s still considered a cutting-edge technology, Green Revolution
Cooling hopes to have a big effect on data centers. As Green Revolution’s
director of marketing David Banys sees it, an oil-cooled data center could be
set up just about anywhere, cheaply. “There’s no need for chillers; there’s
no need for raised floors,” he says. “You can put our servers in a barn
that’s 110 degrees.”

An oil-cooled motherboard. Photo: Intel

Does that oil hurt the hardware in any way? After running the servers for a
year in its New Mexico data center, Intel popped them open them and found
that the oil hadn’t harmed things at all. In fact, because oil-cooled servers
are kept at a common temperature, it may turn out that they’re even more
reliable than their air-cooled counterpart, Patterson says. But that’s an
area for future research.

There is a downside, though. If you need to pop open an oil-cooled server to
change a part, it can get a little messy. One of the Intel techs working on
the tests in the company’s New Mexico data center brought in a change of
clothes each day, just in case he needed to pull the plug, drain the oil, and
tinker with one of the systems.

Green Revolution recommends an oil change every decade.

Still, the CarnotJets are so power-efficient, that Patterson thinks that the
data-center set will eventually want to try them out. “If and when server
manufacturers get around to doing this, then I think the adoption could be
pretty reasonable,” he says.

In addition to removing fans and sealing up hard drives — or switching the
servers to solid state drives, which have no moving parts — server makers
also need to remove the conductive grease between the server’s processor and
its heat sink, because it can leach out into the mineral oil, Intel says.

According to Green Revolution Cooling, at least one server company is getting
ready to ship this type of oil-bath-ready servers: SuperMicro. David Banys
says that SuperMicro should be announcing its servers any day now. SuperMicro
couldn’t immediately be reached for comment.

Watch the CarnotJet in action here:


Top photo and video: Green Revolution Cooling

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