SETI@home: Research on the Research 50
Officer Larry writes "A professor and a graduate student at the University of South Carolina just posted a study into SETI@home work unit completion times. They came up with some pretty interesting results. It stems off Team Lamb Chop's work, but these guys are interested in how much variation there is in completion times if the same work unit is analyzed over and over again on the same system. It looks like they have other studies in the hopper. Warning: there looks to be quite a bit of statistics in this study..."
Linux wussy! (Score:1)
TLC Site down - Here is mirror (Score:1)
Sadly, /. cannot take credit for killing tlc.com, it's been down for a spell already. Come kill my box instead.
-Hagbard (/. - Obelisk) Don't have my login at work... doh.
Re:Statistics and Analysis? (Score:1)
SETI has a small chance of being extremely worthwh (Score:1)
Re:hardware SETI@home ? (Score:1)
Actually testing compilers (Score:1)
Re:WinNT needs 128M ram (Score:1)
wee (Score:1)
Re:Actually testing compilers (Score:2)
Actually, the OS's can make a difference in performance, even with the same calculations.
Memory management is important for speed, because of alignment issues. OS overhead, for task switching and other stuff matters. Disk access, caching and so on are important. How the OS's handle virtual memory can be important.
But the trials did not have enough samples to fully explore the situation anyway. rbb
I wonder... (Score:3)
Re:WinNT needs > 128M ram (Score:1)
WinNT needs 128M ram (Score:2)
I would have said "it is interesting that Windows NT cannot run a WU at full speed with less than 128M of RAM. Other operating systems make effective use of 128M of memory, but NT needs 256M."
Re:does 256 vs 128mb matter? (Score:1)
Code Schmode! (Score:1)
PLUS (Score:2)
Debian 2.2 supports udma100, he should have been runing stable, but in anycase he should state exactly what he installed, and should describe what he removed from cron. A fat desktop system will have tons of programs installed. What he is testing is the performance of setiathome, exim, locate, logrotate, suidmanager, syslogd and half a dozen other programs/scripts all at the same time.
Stats Question (Score:3)
conspiracy (Score:1)
Re:fs (Score:1)
Sorry, really I am... I have a problem... it was just staring at me... so blankly... an empty page without any posts...
I wasn't tring to get first post... really it just kinda happened... I didn't think, I just acted.. I don't know what I was thinking.
Please forgive me... I am a sick man
Oh god.
Re:Whats the point of Seti? (Score:1)
IIRC SETI is privately funded so don't gripe about your dollars going to waste.
Standard Deviations Not Bad! (Score:1)
What they need to do now (as they said) is do more than 5 trials for each configuration so their results are more reliable, THEN trying to decrease their standard deviations by controlling temperature, and other variables.
Figuring out which factors affect computation time would be interesting. Especially how the environment around the computer (temp, pressure, relative humidity
SetiSpy and WINE data (Score:3)
Also one thing that seemed to be missing from this article was reference to Roelof Englebrecht's data, collected over some period of time and posted on his SetiSpy web site here:
http://pages.tca.net/roelof/setispy/
Roelof and TLC's Max, are both the keepers of the TLC benchmark database and Roelof checks each and every submission to ensure that the data isn't corrupted somehow due to an unstable overclock.
In addition, I currently run the text client in WINE on my Red Hat 6.2 as standard practice and have submitted data to the TLC page for it. It runs just fine and in fact runs the WU FASTER (whether using the -win95 switch or the -nt40 switch) than either native winblows version when run on the same system via dual boot.
Re:NO MACS ??? (Score:1)
When I read the Athlon scores vs the Pentium III scores, they aligned with other benchmarks I've seen which compared the two chips. What's more interesting is that the fastest Athlon was 2 times faster than the fastest Mac. One might be tempted to say mhz do matter until you look at the clock on the PA-Risc. At less than half the clock speed, it blows the fastest Athlon out of the water. Looks like HP knows how to build a cpu.
Am I the only one that caught this (Score:1)
Don't amd chips just repsond to i586 optimized instructions, and i686 instruction pairings slow it down?
Re:Am I the only one that caught this (Score:1)
They probably could have fixed it such that linux came out ahead if that was the result they wanted. Though their reasearch does show that reaching for the shelf, and using what is most easily available in a default config can sometimes lead to NT performance wins.
Re:Am I the only one that caught this (Score:1)
If they went into the make file, and changed the optimizations to amd k7 before re-compiling they might have pretended they were way leet, instead of saying "upgraded" the kernel, which suggests they just pointed apt-get to unstable mirrors, and got binaries (which is also alluded to in the next sentence of the article).
Re:NO MACS ??? (Score:1)
Ahh, I'm just kidding. Who cares.
To me, you seem like your life priorities are a bit mixed up. Who cares! It's just a computer - don't wet your pants. Use what you like, and don't talk about what you don't. At least have a valid point.
See you.
Re:NO MACS ??? (Score:1)
Re:Linux wussy! (Score:3)
Re:Whats the point of Seti? (Score:2)
Isn't that more reason to start searching now? You're right -- aliens may have "found" us long ago. So now it's our turn to find them. Later is better than never, no?
any alien dumber than us (i suppose thats what we are looking for) may not even respond
Respond to what?! SETI is a search. It's not a response. Search first. If you find even a "dumb" alien, wasn't that worth the search? As an analogy, do we search for new species on this planet so they can respond to us? Of course not. They're dumber than us, but still worth knowing about.
does 256 vs 128mb matter? (Score:1)
In fact, the statistics show that SETI isn't that memory hungry, the differences between the two memory configurations where almost noise; less than a standard deviation in some cases.
seti@home down (Score:1)
Re:does 256 vs 128mb matter? (Score:2)
As for the fact that it beat Linux, I would guess that the code is optimized for Windows, then ported to Linux.
Also, in my experience setiathome on Linux has blown Windows out of the water...when running without the GUI.
An interesting study, though I'm surprised by their lack of understanding of the memory issue.
Statistics and Analysis? (Score:3)
Also, they didn't seem to consider possibilities like the fact that a default install of RH Linux may run updatedb daily, which if using a slow drive with a lot of files could easily describe the variation. Instead, their first guess is 'unstable packages.' Wazzup? Academics...they love bizarre conclusions in favor of putting in that extra effort to find the truth. They spent enough time setting up the survey...why didn't they finish the job? (Answer: they were working on a deadline...and didn't allocate time to research the variation)
Mirror for Team Lamb Chop (Score:1)
Our web host decided to take the server down for what has turned out to be a couple of day upgrade. We have put up up our site on a mirror in the meantime. You can check out the main Team Lamb Chop page here: tlc.hagabard.com [hagabard.com] and you can check out our benchmarking pages here: tlc.hagabard.com/bench/index.htm [hagabard.com]
Thanks for your support!
-zAmboni
Re:Seti@home hack (not really a hack) (Score:2)
-zAmboni
Re:WIndows NT rocks over open source (Score:1)
Still, who cares reading those company "success stories", no matter which company or product they are coming from. I can't even take these stories serious if it's a product I like/support.
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Tired, (Score:1)
But then again, I can't join since stanford seems to have blocked my entire ISP. heh
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Re:Aliens and SETI (Score:1)
Re:Stats Question (Score:2)
Are the same WUs? (Score:1)
However, I doubt the differences in that kind of data are enough to justify the Linux performance by itself.
Rather a studid article anyway. (Score:1)
Re:NO MACS ??? (Score:1)
If you could afford a top-end machine, of course.
All I know is Macs sure aren't taxing their CPU's at home playing games...
Re:Whats the point of Seti? (Score:1)
> wrong as he could be.
Is he?
Saying 100 light years wouldn't make us detected is like a caveman saying, "Gee, we can't throw a rock more than 20 Oog-lengths, so no one will find us!" Meanwhile, a satellite with square-inch resolution orbits overhead and spots the campfire at nighttime with no problems whatsoever.
We probably are found, and the fact we don't see a galaxy filled with immensly powerful artificial signals indicates either we are being directly shielded, or the standard galactic communication is hidden, piggybacked on background radiation ala Contact, or my favorite theory, there's much better ways to communicate than radio waves, so the period of EMF useage by a civilization is very brief.
Re:Avg. time (Score:1)
L2 Cache seems to be the most important factor (Score:2)
While we haven't done anything nearly as scientifically viable as this study, our conclusion has been that the difference in processing speed between a 1Ghz and 866Mhz Intel processors (each with 128M RAM) is very slight - almost imperceptible in some cases.
Systems with larger L2 caches, however, seemed to have distinct performance advantages. How (or if) you can apply that information to non-SETI applications I will leave to you.
-Coach-
Aliens and SETI (Score:1)
NO MACS ??? (Score:3)
I can't believe they didn't test any Mac platforms. Mac users are some of the most enthusiastic fans of SETI! Team MacAddict is #3 in the Club Competition [berkeley.edu], only behind Ars Technica and Team Art Bell. If fact they're almost tied with Team Art Bell, with only 5,000 users to Art Bell's 13,000 users !!
Re:Statistics and Analysis? (Score:1)
But I also don't understand why they chose to test the "variance" of two operating systems using the SETI program. What they are comparing is the run-time reliability of two completely different binaries. Even if they're compiled from the same source code, a large part of the variance can presumably be explained by the integrity of the compiler.
Don't be so hard on academics though... ;)
hardware SETI@home ? (Score:1)
Response from the authors (Score:2)
It's good to see such a strong response from the community and we thank everyone that has given us constructive feedback. However, we feel that many of you have completely missed the purpose of the article.
The purpose of the article is NOT to compare OSs, get fast SETI@home times, or even to optimize the systems at all. We thought this was clearly stated in the abstract and methodology sections. Either we screwed up and did not make this apparent or people did not read the article. The study of optimizing systems and making SETI@home faster is already handled very well by Team Lamb Chop [teamlambchop.com] (if the site ever decides to come up...).
What we DID want to accomplish is to study work unit completion time VARIATION . This question was prompted by our reading of the SETI literature which had not dealt with this matter. Our research question was: on a "typical" system, how much does the completion time vary from instance to instance? If I run the same work unit over and over, how much will my completion time vary? I don't know about the rest of you, but when I run SETI@home on my systems, I do not disable all other processes (including cron or anything else). If we did disable anything out of the ordinary, then we did not accomplish our goals. As was clearly stated in the methodology section, we used the default settings for each OS.
A separate question was the method used for us to arrive at this conclusion: testing several OSs in several configurations on the same platform. At this time, this method seems a useful one for comparing configurations.
Now that we have a baseline, we are going to continue and try to figure out the questions posed in the article. Such as: why does Linux have such a high variance in comparision to the other OSs? We have collected many great suggestions and I will test all of them and post the results.
In any case, this article cannot be used to compare OS to OS performance. Not only is that not the purpose of the article, but there are too many confounding variables--many of which have been raised here.