Google claims to have the most efficient data centers in the world, but keeps its secret sauce close to the chest, revealing only tidbits of information about its servers, like how standardizing on 12 V power supplies instead of using multiple voltages adds efficiency.
So last month when I read an EE Times article called “Server Makers Get Googled” that reported Rackable Systems Inc. would start shipping for its CloudRack enclosures 12 V-only motherboards with two servers per board in early 2009, I was quite interested. Could it be that server vendors have decrypted Google’s recipe for efficiency and will now offer it up for sale to the lilliputians of the IT world?
- So, as a journalist that Rackable typically keeps in the loop, I felt a tad overlooked after reading all this buzz and emailed my Rackable contact to ask about this exciting new Google-esque product.
The folks at Freemont, Calif.-based Rackable said the reporter incorrectly inferred that Rackable was going to be delivering 12 V enclosures. “That information was taken out of context from a panel discussion, which included the mention of Google’s 12 V servers and Rackable’s CloudRack,” a Rackable spokesperson said.
Geoff Noer, Rackable’s Vice President of Product Management, called to explain today that though the company isn’t offering a 12 V rack, the company started shipping 12 V motherboard options for its servers in Q408.
And I suppose if any vendor were to give 12 V server enclosures a shot in the commercial market it would be Rackable Systems, because the company has a history of going off the beaten path when it comes to servers and server power; it introduced the first large-scale X86 DC-based servers and storage in 2003, and sells half-depth 1U, 2U and 3U servers for added density.
The benefit of using a single-voltage power supply (12 V) for hardware is added efficiency. Today’s server power supplies convert 110 V AC power to DC power at 3 V, 5 V and 12 V, which, according to Google’s website, wastes up to a third of the total energy consumed by a server before it ever reaches the computing components.
Google designs its servers to perform a single conversion to 12 V, which is then further converted to other voltages by the motherboard, reducing power loss during voltage conversions as well as heat output and power loss, according to this article about Google’s 12 V model on Nemertes Research.
Noer said that when comparing Rackable’s single 12 V motherboards to those using multiple voltages, the single output supply is 91% efficient — 3% more efficient than the multi-output option. “It doesn’t sound like a lot, but that 3% adds up to a lot of watts saved,” Noer said.
Apparently, whether a vendor uses a single output or a multiple output makes no difference to the end user because the power distribution happening within a server is not visible, Noer said.
Though Rackable does not have any plans to offer 12 V power at the rack enclosure level at this time, there is interest in it because it would add more efficiency by eliminating individual server power supplies, Noer said.
“As part of a rack-level or blade enclosure solution, 12 V-DC power distribution has appeal from the standpoint of eliminating individual power supplies, simplifying power delivery and improving power efficiency,” Noer said. “Such systems would still appear to be AC solutions from the users’ perspective, since they would be providing AC power to the rack or to the blade enclosure even though the internal DC distribution would be 12 V-DC-based.”
Noer said he’ll let us know “if/when” Rackable offers 12 V-based racks. Stay tuned.