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1) Message boards : Number crunching : Last wu crunched - kind of a sad feeling (Message 5007) Posted 7 Nov 2004 by Post: Fewer credits per work unit , less time per work unit but more work units processed The end result is same credits for same processing time but more work is done , better for the science that way so no real loss to credits :) Dave
2) Message boards : Number crunching : Last wu crunched - kind of a sad feeling (Message 5001) Posted 7 Nov 2004 by Post: Same here ,, out of work , I�ve switched back to seti as the 4.07 seems to have fixed the slowdown problems there when lhc comes back on line in dec / jan I will revert back to 100% lhc I did find something of a bug in the process If you set lhc at 200 and seti at 100 and to use 3 cpu�s I found that if there�s no work from lhc then it will only download enough from seti to keep 2 of them happy and leave 1 cpu idle ? Thought if there�s no work from one project it would compensate and use the available capacity on another project Dave
3) Message boards : Number crunching : Official Word on no more Work Units...!!!! (Message 4991) Posted 7 Nov 2004 by Post: Under LHC@home preferences Should LHC@home send you email newsletters? = yes I should check it, so at least they know you would like them to Dave
4) Message boards : Number crunching : copy to dev temp (Message 4990) Posted 7 Nov 2004 by Post: Oops thought this was in the caf� Dave
5) Message boards : Number crunching : copy to dev temp (Message 4989) Posted 7 Nov 2004 by Post: Protester waives right to free speech New York City, NY-- In a strange twist today, a political protester waived his right to freedom of speech during an organized march through Times Square. The march was held in an effort to raise awareness of the number of registered voters who are working to remove President Bush from the White House in November. "The injustices that have weighed upon this country are unspeakable." said Bernie Fresh, or "B-Fresh" as he is known among his constituants. "Today, I am refusing my right to express myself freely, in protest to the joke that President Bush has made this nation out to be." The march was organized by a political activist group known as P.F.P. or "People For Protesting". Diana Hunter, spokeswoman for P.F.P. said this regarding B-Fresh: "I think it's great what he's doing. Our right to free speech has already been stripped away by this administration. We run a great risk by even being out here today. At any moment we could be arrested and trucked off to jail. What Mr. Fresh is doing is playing it safe. Sort of a new form of silent protest. If he doesn't speak out against the government, then they can't charge him with anything." B-Fresh is a full-time student. He is majoring in environmental studies at the California Institute of Technology. He plans to some day make a career out of river rafting. "Ghandi ain't got nothin' on me." he said when asked about his revolutionary protesting technique. Mahatma Ghandi devoted his life to promoting a strong philosophy of non-violence. Ghandi invented new forms of political protest such as staging hunger strikes, and silent-protest. These techniques were perfected by Martin Luther King Jr., who fought to end racism and biggotry in America. "It's not really all that hard to do. I'm simply denying myself my god-given right to free speech. I'm not displaying any banners, I'm not holding any signs, I'm not shouting any cute rhyming slogans about how much I don't like Bush. I'm just here to march among my fellow protesters, and not voice my opinions." said B-Fresh while standing on a podium and speaking through a bullhorn. by Manic Velocity
6) Message boards : Number crunching : Credits an alternate view and proposal & query (Message 4917) Posted 5 Nov 2004 by Post: Sorry that part of this is a repeat of one I just posted on seti@home But here I would like to address something that potentially may have this effect here If when the new server�s come on line and the credits have to be reset That a league table for the results already done are published, Although the science is of primary importance there is competition between users and groups based on these, for some it�s the only reason that they run LHC@home and other Boinc projects � Credits an alternate view and proposal I propose the following change to the credit system (With the addition of another credit counter for this) That at interval ether monthly or yearly the credits are �reset� With the credit that was acquired for that period a league table of:- Top County, team and user statistics for that period are then published This is for 3 reasons Firstly it will provide more competitiveness between individuals and teams It will reflect the effect that a new team can perform in the rankings As some have been processing for years and others for a short time it will provide more excitement to the rankings Secondly when the project does end, the totals can still be calculated for total credits accumulated per individual/team/country statistics Thirdly it will provide a good indication of user trend for that period I don�t know how others feel but I understand it could be better this way It would not affect the science But as many appear to be in it for the credits It would add competition in the meantime And total credits would not be affected � Dave
7) Message boards : Number crunching : at what times are online for up and download (Message 4913) Posted 5 Nov 2004 by Post: I seem to think what was being asked by Guido is At what times are the servers online for up and downloads On a day to day running not unscheduled outages It appears to go off line about 11pm GMT normally and comes back on line around 3 to 4 am but a clear picture of the times would be useful Dave
8) Message boards : Number crunching : work unit processed not in results (Message 4846) Posted 4 Nov 2004 by Post: Odd work unit ? Was checking the results and it showed 3 work units in progress But the pc was showing 4 I checked the work units numbers and refreshed the results page But still only showing 3 The work unit finished and still didn�t show in my results list I can�t remember the number of the particular work unit but has anyone else had this happen ? Wonder if that�s why some complain of the credits being out Dave
9) Questions and Answers : Windows : Boinc/sixtrack failure to correctly allocate multitasking of WU�s (Message 4654) Posted 30 Oct 2004 by Post: i was previously using 4.13 on seti but had problems with it in that it was stoping other apps starting up or letting them start but real slow trying it again it appears to be ok at the moment on lhc time will see .... Dave
10) Questions and Answers : Windows : Boinc/sixtrack failure to correctly allocate multitasking of WU�s (Message 4649) Posted 30 Oct 2004 by Post: Bonic 4.09 / sixtrack 4.47 lockup When there is low work and only 1 work unit being processed (rather than the usually 2) Bonic / sixtrack locks up It has done this a number of times causing the loss of 1 wu so far As it�s a multiprocessor system with 4 available CPU�s the option is set for sixtrack to use 2 of these I�ve been observing the situation and its consistent , as soon as 1 of the last 2 units are processed the cpu time remains the same usual 50% but further study shows that the o/s time shows a marked increase when only 1 wu is being processed Feel that boinc/sixtrack is failing to resolve the fact that just one of the 2 available slots have work and is trying to start the other process without any causing the error A similar problem also occurs if the computer is restarted when your server is down as it cannot get the preferences from the site I�m not able to determine if it�s a problem with boinc or sixtrack though Other than this it works fine o/s is windows 2003 enterprise server cpu type 2 * Intel xeon 2 Ghz no other boinc project�s being processed Dave
11) Message boards : Number crunching : @Markku - homogeneous redundancy (Message 4620) Posted 29 Oct 2004 by Post: >Pentium 4 FPU registers are 128 bits wide. P3 is 64 bits wide yes but a float32 instruction yields a 32bit result regardless of the capability of the fpu returning a 64 bit one would require a rewrite of the code that was using it and it would become a float64 ... same situation but loosing those processes not able to handle 64bit floats Dave
12) Message boards : Number crunching : @Markku - homogeneous redundancy (Message 4610) Posted 29 Oct 2004 by Post: Off topic but A rough calculation of the error could give a difference of about 0.000027 mm on a 1,000,000 turn calculation Between the amd and the Intel fpu's And an actual error on both of approximately the same amount Dew to the limits of 32 bit maths Dave
13) Message boards : Number crunching : @Markku - homogeneous redundancy (Message 4597) Posted 29 Oct 2004 by Post: If you check your results and the processes that have also completed the work units (verified results) I think you will see that platform differences are not proving to be an issue at present I should also add that from how I read it homogeneous redundancy can be turned on and off by � Alternatively, you can enable it selectively for a single application by setting the homogeneous_redundancy field in its database record. � It is also beneficial to leave it off as it can be useful to know if the inconstancy between platforms starts to be a bigger problem And if one particular platform started to constantly fail / then it would become noticeable quickly rather than having to re issue All work units given for that platform And what�s the use of allowing for a possible 100% incorrect but valid results when the platform they where processed on gave them the same error That with homogeneous redundancy enabled would only provide an incorrect picture of the simulation that would lead to bigger problems and cost lots of time, expense and possibly redesign of the LHC to compensate for a non existent correction If there are differences between results from platforms then there is a problem in the maths some ware If not then the calculations are fine and good data is being collected And what better way to ensure that data is valid than to have valid cross platform results that are valid Dave
14) Message boards : LHC@home Science : Thoughts on String Theory. (Message 4575) Posted 28 Oct 2004 by Post: Interestingly re �time� prior to big bang And speed/time relativity the following applies (that is part of the reason that accelerators like CERN can conduct experiments) The closer an object travels to the speed of light the slower the effect of time on it A particle with a half life of a few milliseconds can be effectively extended a by propelling it at �almost� light speed so it remains in existence for a few seconds This also would equate to:- �Without including acceleration time� if you where on a space craft leaving earth and travelling to say Sirius at 6ly distance, travelling at .99999999999% the speed of light From earth as the observation point it would take 6 years for you to get there and 6 to get back But dew to the time displacement caused when travelling at that speed only a couple of seconds would pass to anyone on board The problem with saying time did not exist prior to the big bang is not strictly true just that the speed that all the particles where travelling at would affect the conception of how time is calculated So a measured time of 1E-9 th of a Second may be equivalent to more than the 14Bn years we know it to have existed, As prior to the big bang the temp is believed to be that high that the particles that form matter where moving too fast to form it, probably faster than light if not at it As to the speed of light I feel there are particles that do travel faster and don�t naturally conform to Einstein�s theory but feel to do this they would probably not be �classed� as particles of matter, matter would be transparent to them, but his laws do govern all matter As to � It is really a stretch to try to let go of our current understandings of time and space to try to imagine this phenomenon. I have not accomplished this feat, although I continue to try. � hmm well infinity (full of energized particles) ok, in an opaque state (no photon particles, every thing is moving to fast for that and too hot for matter to form), time well 2.0Exp(4Exp99) (exponent has exponential value) years pass for every word of this your reading, suddenly there�s a cooling effect causing the particles to cool and slow and drop speed and this is the start of the big bang! (Or the end of it?) Sorry I fail to understand how this can be the start of everything time is there just distorted by the heat, and �matter/energy� of some sort is there it did not appear from knowere just prior to it instead was probably in that state for a long time ,, a very long time , just because we have difficulty comprehending how long and any time distortion that its original state would impose upon it The fact that its existence time cannot be calculated is dew to the fact that everything was also under the same conditions and would suffer the same time distortion, and it still is not producing matter from nothing! Just producing it from a form of it that we still cannot detect (too hot, too fast) just that it appears to be hidden its probably just as easy to conclude that 99.999� % of it just vanished leaving space there if it was not for the fact that there�s a measurable expansion rate or is that just another odd distortion ? (This is also included in part of the big bang theory as what happened to most of the matter generating particles anyway) But E=mc2 would say something about the disappearance of 90% of everything wouldn�t it? Yet another small book Dave
15) Message boards : Number crunching : @Markku - homogeneous redundancy (Message 4570) Posted 28 Oct 2004 by Post: no not to do with a hardware error/fault but found this to do with "mathsworks" quote """ The Repeating Sequence block generates different numbers on Windows than on Linux. The differences are slight: on the order of 1e-16. However, the differences can be significant when simulation results depend on comparing the generated sequence, e.g., to zero. A workaround is to quantize the output of the Repeating Sequence block so that values near 0 become zero. For example, you could put a Dead Zone block with zone [0...1e-15] between the Repeating Sequence block and the block performing the comparison. """ on same hardware platform ! Dave
16) Message boards : Number crunching : @Markku - homogeneous redundancy (Message 4559) Posted 28 Oct 2004 by Post: but is there also the case where difrences in the way diferent opperating systems interact with the fpu also that can lead to diferent results on the same fpu but under diferent opperating systems an example if the last bit is rounded diferently between diferent o/s genraly a 32bit floating point calculation contains an extra result bit(s) that are striped from the result but it can be possible for the os to detect it and carry its state to the next calculation diferences here would arrise if one o/s reset this each time and another passed this to the next calculation this would give the situation that diferent opperating systems gave differing results also or that the opperating systems are using one of the other floating point number formats (i beleve there are a few standards for the binary representation of a floating point number) although im not shure what standard is used by each o/s Dave
17) Message boards : Number crunching : @Markku - homogeneous redundancy (Message 4554) Posted 28 Oct 2004 by Post: Correct me if I�m wrong As an example for it:- If one fpu type calculates the ring to be 27,000,001mm long and another 26.999,999mm then the results differs by 2mm That would be out of the validated range as its probably looking for differences of a couple of microns (Although I don�t expect the above example to be correct but demonstrates the problem) Data can be used from differing fpu types the point of the particle at the end of the calculation should be consistent with the formula used within the fpu so as like shown in the above example it would differ between different fpus Collectively 3 results on one fpu type should match, And 3 correct results for a different fpu type with the same WU would mach but together you would end up with 2 different results What matters is you know the spot you want it to be at (that would show as different for each fpu type) and what matters is where it ends up (that�s relative to the spot you want it to be at) Calibration of the results should be possible but that is a math problem and not something the validator would have enough time for the compensation "constant" value that would be needed to correct it would differ depending on the workunits lenth Suppose its better that work units are given to machines with the same fpu type As it saves validation time and processor load Dave
18) Questions and Answers : Windows : disk space and drive allocations (Message 4470) Posted 27 Oct 2004 by Post: guess so thanks for the reply dave
19) Message boards : Number crunching : How is the "user of the day" being determined? (Message 4462) Posted 27 Oct 2004 by Post: but theres 2 users of the day ??? the one shown on the main page and always a diferent user of the day is shown on the participant profile page Dave
20) Questions and Answers : Windows : disk space and drive allocations (Message 4433) Posted 26 Oct 2004 by Post: how do i get boinc to use space on a diferent drive for its work space i have 2 drives the c:drive is 40Gb and is used for the os and programs the second D: drive is 160Gb and is for data only the only way i can see is to mount the drive as a directory on c:/programfiles/boinc but this would remove it from its current position and although give boinc extra space it would not allow access to d: as a seprate drive and other data that is on it would all end up under c:/programfiles/boinc O/S is windows 2003 enterprise server David

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