"[Other vendors' switches] choked. They were losing packets and they were losing data," said Dan Werthimer, chief scientist of SETI@home, the volunteer research arm of the Search for Extra-Terrestrial Intelligence (SETI) project at the University of California, Berkeley. "If you're looking for ET and you're missing part of the [radio] spectrum because you've dropped some packets, you lost your opportunity to get a Nobel Prize."
Starting about five years ago, SETI scientists -- who run the SETI@home project -- gradually upgraded their 1 Gigabit Ethernet switches in their data centers around the world. UC Berkeley replaced SETI's 1-Gigabit switches from Fujitsu, HP ProCurve, Cisco Systems, Fulcrum and Force10 with 10 all-Fujitsu 10 Gigabit Ethernet switches.
Researchers at UC Berkeley's Center for Astronomy Signal Processing and Electronics Research built the rest of SETI@home's network themselves, Werthimer said. The systems are used at 30 universities and radio observatories around the world, ranging from California to China.
"We mostly build our own specialized computing hardware, typically made out of FPGAs (field programmable gate arrays)," he said. "FPGAs do very high-performance supercomputing."
By downloading software from the SETI@home website, 8 million volunteers in 200 countries run a screensaver that utilizes spare computing cycles to process for radio signals for SETI and return their findings.
Capturing millions of frequencies from multiple star systems simultaneously with 42 radio telescopes in northern California, the project assigns volunteers their own corners of the universe to inspect as their computers idle.
Although the lines have been silent of any indication of intelligent life, Werthimer said the 30-year-old project has had other successes, such as illustrating the first images of a black hole at the center of the galaxy.
"Together, the SETI@home volunteers have formed our planet's most powerful supercomputer," he said. "The capabilities have been doubling every year. In the '70s, we listened to 100 channels. Now we're listening to billions."
But with their capabilities, the scientists' demands grew also. Power from the telescopes, which resemble small satellite dishes, is combined to create one giant telescope, Werthimer said.
"We have millions of packets per second. Every port we were pushing 10 gigabits per second -- right up to the maximum," he said. "The most important thing for us is to handle the full aggregate bandwidth -- every port being able to talk to every other port at the maximum rate."
10 Gigabit Ethernet was about more than horsepower
When upgrading their gigabit rack switches about five years ago, scientists sought more than just the horsepower of 10 Gigabit Ethernet switches to push data through their homegrown servers. The SETI project also requires flawless network performance to ensure that no radio signal in the universe goes unnoticed.
"We have very high, unusual requirements," Werthimer said. "We have very high data rates going onto every port on the switch … [and] the switches we found from Fujitsu could do it. Some of the other vendors' switches couldn't."
Jim Preasmyer, director of sales and business development for Fujitsu, said the 10 Gigabit Ethernet switches have such meticulous performance because of Fujitsu's proprietary application-specific integrated circuits. The SETI@home project uses Fujitsu's 20-port XG2000C, which offers 400 Gbps non-blocking throughput, 300-nanosecond latency and a 3 MB buffer.
"We don't drop packets," Preasmyer said. "We did some performance testing with a third party … [that] passed over 6 billion frames through our switch, and we didn't drop a single frame."
By upgrading to 10 Gigabit Ethernet, the SETI project and SETI@home can aggregate data from the small satellites to examine more frequency bands and have more sensitivity to find weaker signals, Werthimer said.
"[Dropping packets] means the search gets a little weaker," he said. "If you're making images in the sky and making maps, the images aren't as good."
With the technology and abundance of volunteers, Berkeley scientists can analyze thousands of years of computing time every day, Werthimer said. Already, they are counting the days until 100 Gigabit Ethernet switches hit the market.
"We want to analyze more and more of the band -- more radio channels. We want to expand the telescope out to add more and more antennas," he said. "It's going to be more and more demanding, so eventually we're going to have to figure out how to handle hundreds of terabits per second and many petabytes…. We're kind of hoping Moore's Law will continue, and then we'll have a chance at finding other civilizations."
Let us know what you think about the story; email: Jessica Scarpati, News Writer