SETI@Home Turns Four

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Date: Thursday, May 29th, 2003, 13:40
Category: Archive

Update on SETI@Home distributed computing project. Includes overall project statistics and news, Team O’Grady stats, and basic instructions onhow to join Team O’Grady. Read More…


SETI@Home Hits 4
The month of May 2003 marks the fourth anniversary of the SETI@Home distributed computing project. The numbers for the entire project are mind-boggling:
- Over 4.5 million registered users
- More than 897 million work units have processed
- The cumulative CPU time represents 1.47 million years of processing time
- On an average day, the project runs at more than 50 teraflops per second.
In March 2003, the University of California at Berkeley team that manages the project re-visited the best signal candidates. The scientists at Berkeley define a candidate when it has two or more ?events? (events can be spikes, Gaussians, triplets, or pulses) detected from the same location in space at different times. To narrow down thousands of possible candidates to just 150 for re-observation, the Berkeley team looked to see if the signal matched one of the following characteristics:
- Its location matches the location of a known star
- Its location matches the location of a known planet
- Its barycentric frequency is constant across time but cannot be attributed to RFI
The team was able to re-observe 166 signal candidates plus 61 other sources considered interesting (extra-solar planetary systems and nearby sun-like stars) during a one-week period at the Arecibo Radio telescope in Puerto Rico. Although the team discovered no evidence of a signal from an extraterrestrial civilization during a quick, real-time analysis of the data, they sent out the signals to SETI@Home users around the world for additional processing.
Team O’Grady
Readers of the PowerPage have contributed to this effort since the very beginning of the project. Team O’Grady has almost 1,200 members who have processed more than 777,000 work units.
So are you sitting there saying “Well, this sounds cool and I’d like to join, but I’m four years late?”
A bit behind maybe, but not late.
You can download SETI@Home client applications for either OS 9 or OS X (or for Windows, Unix, Linux, etc) here. There are two versions for OS X: one with a graphical interface and one that runs from the Terminal (a.k.a. the command-line or Darwin version).
The command-line version runs significantly faster than the graphical version. You can get it here. Another link you’ll need is the one to join the team.
What to Expect
After downloading the fairly small client app and launching it, you will be asked to enter a user name. The client app will then download a 350KB file that contains the small slice of the radio spectrum. This file is called a work unit. After a few hours, your Mac will complete that work unit and then connect to the servers at Berkeley to return the results (about 4KB) and download another unit.
How long does it take to process a work unit?
A 1GHz G4 iMac running the Darwin version of the client app takes a little over 8 hours on average. The SETI@Home client is not optimized for Altivec, but processing times are fairly proportional to processor speed across platforms. For example, a 1.8GHz Compaq desktop will crunch a work unit in 5:10. And yes, you can be on a Mac team with a computer that uses other operating systems.
Let’s say your 800MHz TiBook turns out 2.5 work units per day. In just one month, you will have moved up almost halfway up on the team list. You can keep track of your progress (and the teammates you’re trying to pass) at the PowerPage’sUnofficial SETI@Home Stats Site.

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