Posts by Lord Crc

1) Message boards : News : Status 12th August (Message 24600) Posted 14 Aug 2012 by Lord Crc Post: My PC is contributing to LHC@home for science, not for credits. I'm very pleased that LHC@home is going strong again, and that I can contribute ever so slightly to the most awesome machine built so far.
2) Message boards : Number crunching : Strange 1st wu (Message 22241) Posted 18 Apr 2010 by Lord Crc Post: IIRC this can happen if the simulated beam parameters does not lead to a stable beam, such that the beam just crashes into the wall of the detector immediately.
3) Message boards : Number crunching : Why BOINC 6.X has issues with LHC@home and other things (Message 20781) Posted 18 Nov 2008 by Lord Crc Post: Nice try but guess again. So, where in the world can you divert funds from a gov\'t funded research project by simply \"[speaking] to the right person\"? [quote]Fools and their money always part quickly.[/qoute] I\'m gladly giving less than $0.1 a month to what I consider the most impressive project since the great pyramids were built. If you think that\'s foolish, fine for you, I couldn\'t care less. Personally I think it\'s great that I can contribute, even if it\'s just a tiny tiny bit.
4) Message boards : Number crunching : Why BOINC 6.X has issues with LHC@home and other things (Message 20778) Posted 18 Nov 2008 by Lord Crc Post: Regarding diverting funds... there is someone who can divert funds, there always is. If funds haven\'t been diverted then you just haven\'t spoken to the right person or else you have but they\'re pretending to be deaf. In other words, you have absolutely no idea what you\'re talking about at all. As for me, I consider the scientists time more valueable than my CPU\'s idle cycles.
5) Message boards : Number crunching : BOINC 5.10.x?? (Message 20276) Posted 12 Sep 2008 by Lord Crc Post: I\'m a bit confused here. I upgraded to 6.2.18 since I was having some vista issues with 5.x, and as we speak it seems to be happily churning on LHC WU\'s (I\'ve even completed a few and gotten credits for them). What exactly is the problem with 6.2.x?
6) Message boards : Number crunching : How often does LHC shut down? (Message 19547) Posted 26 Apr 2008 by Lord Crc Post: I'm guessing the points were that a) money/grants aren't issued based on who's whining the most (or so the theory goes) b) the lhc is running over budget, and besides cern isn't the only player involved with the lhc...
7) Message boards : Number crunching : Initial Replication (Message 19260) Posted 17 Mar 2008 by Lord Crc Post: Fast turnarounds can be achieved by IR > Q, but they can also be achieved (without wasting cycles) by short deadlines. Short deadlines won't fix the AMD / Intel issue though... But I agree that the deadlines are very "lax", and could be tightened a lot.
8) Message boards : Number crunching : Initial Replication (Message 19254) Posted 17 Mar 2008 by Lord Crc Post: Well Neason or Alex??? In this very thread there has been given two very plausible answers to that question. From what I can see, it boils down to the following: This project has a very high host / wu ratio. This means that the extra replications (>3) can be computed essentially "for free" (as seen by the server). Imagine running one WU on an 8-way SMP box... Assuming a CPU bound program, using an IR of 3, 5 or even 7 wouldn't make much of a difference in terms of completion time of the WU. So the extra replications can be done "for free". If the error rate was zero, a high IR would lead to a shorter time to completion, because there's a higher chance that three of those replications would get crunched by fast computers. Since the error rate is not zero, using a high IR still leads to a shorter completion time, since there's a higher chance that at least 3 of the 5 results agree. This is especially true, considering what Alex mentioned regarding Intel vs AMD results. As mentioned in this post, it would seem that the above theory has indeed been confirmed during testing. The "problem" with Dagorath's analysis, as far as I can see, is that it assumes a lower host / wu ratio, and so it does not apply to the current situation (I believe he said so himself). If the extra replications cannot be computed "for free", then his analysis holds. Personally, I'm all for completing the LHC as soon as possible, regardless of how many "wasted" CPU cycles my computer must perform. If you'd rather spend your CPU cycles on something else, then do it :)
9) Message boards : Number crunching : Please increase our daily machine quota (Message 18130) Posted 13 Oct 2007 by Lord Crc Post: That will be possible after they upgrade the server. Ah excellent. I just read that they could do a more "fair" distribution, but not exactly what "fair" meant :)
10) Message boards : Number crunching : Please increase our daily machine quota (Message 18116) Posted 13 Oct 2007 by Lord Crc Post: I would be very happy with a 2 pending wu's per core quota. So that when I finish one, I can grab another. Having one backup wu is nice in case there's a network problem or whatever.
11) Message boards : Number crunching : Bad thread priority (Message 17488) Posted 21 Jul 2007 by Lord Crc Post: LHC had one thread on priority 15, another on 2, another on -2 (if I remember correctly). Changed all threads to -15 and no more computer lag. (SetPriority doesn't let me change priority of individual threads) Maybe this app got Lowest and Idle names swapped, but there you can see the numbers... It was -2, should be -15. The terminology used by that program does not correspond to the terminology used by MS. It seems like "lowest" actually means THREAD_PRIORITY_IDLE. In which case it's 1 step down from what it currently uses (IDLE_PRIORITY_CLASS + THREAD_PRIORITY_LOWEST). If that really makes such a difference, my money is on a third party application/driver/voodoo.
12) Message boards : Number crunching : Bad thread priority (Message 17473) Posted 21 Jul 2007 by Lord Crc Post: But there is one priority even lower than Idle, called Lowest! I set it to Lowest using a 3rd party program and my computer stopped being sluggish. This doesn't make sense to me. First, Idle is most certainly the lowest priority class, and thread priority. You can read up on them here: http://msdn2.microsoft.com/en-us/library/ms685100.aspx Second, ProcessExplorer shows SixTrack in the Idle priority class, and the worker thread as having a priority of 2, and as you can see from the table in the above link, that means Idle class + Lowest thread priority. If you can reproduce this, dowload ProcessExplorer and check out the priority of the worker thread. I'm guessing a third party is messing things up though.
13) Message boards : LHC@home Science : If Neutrinos have no mass, can they escape a black hole? (Message 16015) Posted 3 Jan 2007 by Lord Crc Post: I know this is probably a stupid question, but if photons have energy, and energy is mass, and anything with mass must travel slower than speed of light, doesnt that mean that light itself moves slower than the speed of light? Here's a link that might help clear up the issue: http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html Short version is: There's mass, and there's mass. Don't confuse the two :)

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