Posts by old_user36660

1) Message boards : Number crunching : Should I run this model? (Message 38015) Posted 21 Sep 2009 by old_user36660 Post: I can see how processors of different brands can produce slightly different results, due to special algorithms they use. However, as far as crunching on similar processors goes, there should not be any difference, unless one of them is overclocked and produces errors. Speaking of which, let me go back to my Mid-Holocene model in question. http://climateapps2.oucs.ox.ac.uk/cpdnboinc/workunit.php?wuid=6535949. The first machine already completed the run, while mine and another one â€“ apparently heavily overclocked - have phase one completed. If you care to compare the three phase 1 temp and precipitation graphs (all 3 cpus are Intel core2duo), you can clearly see how two of the graphs are identical, while the third one, produced by the oveclocked machine, differs. As far as I can tell the overclocked machine miscalculates and it does more harm than good to this project, since it takes a third machine to verify the results of the other two. Overclocking while doing DC - not a good idea..
2) Message boards : Number crunching : Should I run this model? (Message 37997) Posted 15 Sep 2009 by old_user36660 Post: Thanks for your advice. Does that mean some values are randomized on each run of the same model, so that each run is unique?
3) Message boards : Number crunching : Should I run this model? (Message 37995) Posted 15 Sep 2009 by old_user36660 Post: A couple of days ago I was excited to see my first Mid-Holocene model downloaded. Then I noticed the same job has been already assigned to another computer nearly a month ago, where it is about to be completed (phase 4 now). I started wondering if it would make much sense for me to do the same work but realized that maybe I could verify the other personâ€™s findings. Meanwhile, the same model has been assigned to yet another person and, since his system is faster than mine, he will probably beat me to the punch too. http://climateapps2.oucs.ox.ac.uk/cpdnboinc/workunit.php?wuid=6535949 So, considering that it will take nearly a month of nonstop crunching on my system to do this job, and by that time it will be completed at least once (likely twice), isnâ€™t my computer going to be more useful working on another model? I realize that I will be getting the full credits either way, but credits are really not what I am after in this project. I would like to know that my computer is doing a valuable scientific research and not just replicating known data. So what do you guys think I should do? Should I go for it or abort it and get another model?
4) Message boards : Number crunching : HADAM3P's too much RAC weight? (Message 37965) Posted 9 Sep 2009 by old_user36660 Post: Don\'t HADAM3P use the more advanced SSE2 instruction set on cpus? If so, they do more calculations per clock and boinc might expect that they would be awarded more credit. Just my thought on this.
5) Message boards : Number crunching : Credit granted, no work done? (Message 37961) Posted 8 Sep 2009 by old_user36660 Post: Hi, I was skimming through the top computers stats page and came across this fellow: http://climateapps2.oucs.ox.ac.uk/cpdnboinc/results.php?hostid=892711. Apparently, his client gets detached shortly after he downloads a work unit and then he receives full credit for that work unit. Is this a BOINC problem or some sort of cheating?