Author: Wayne Lowrance
Date: 21:39:30 09/03/02
Go up one level in this thread
On September 03, 2002 at 22:10:22, Robert Hyatt wrote: >On September 03, 2002 at 20:00:56, Vincent Diepeveen wrote: > >>On September 03, 2002 at 19:54:41, Robert Hyatt wrote: >> >>How can you calculate speedup based upon node counts >>instead of time? > >I don't, and I didn't. As I clearly said. I calculated the speedups >directly from the log file times. Then I was asked to supply node counts >which are _impossible_ to produce due to the way the test was run and the >way Cray Blitz (and crafty btw) counts nodes during a parallel search. > >So. Speedups were computed normally. In the log file, for anyone that has >ever seen Cray Blitz run, we produced a continual display of how busy each >processor was. I could tell at any point I wanted "how much of each processor >has been devoted to searching nodes only? (as opposed to spinning or whatever). > >Given that data, which in the case of Crafty is the cpu% that it displays in >the log files, I can easily compute a node count that will be _very_ close >to what is searched. IE in crafty, the cpu% is computed by _me_ and it is not >just total cpu time divided by wall clock time. I'll let you look at the source >to confirm that it is only time spent actually _searching_ that is counted... > >That is how the node counts were produced, since I was not doing searches to a >fixed depth, because I used the actual game log for the 16 cpu numbers, so that >I could just use an 8cpu C90 for the rest which was easier to get access to. > >Clear enough??? > > >> >>Where is the accurate time table if your latest statement now >>is that the time table in journal of icca is not correct? > >The speedup numbers in the JICCA paper are _exactly_ correct. As I have >told you all along. I had no idea you were on a node count tangent, even >though I have certainly told you often enough "I can't display node counts >when the pv changes because I don't count nodes that way... I couldn't do >it in Cray Blitz for the same reason." So you should have known what I was >talking about, but aparently not... > >There are three tables in the JICCA paper. > >1. speedup. This is correct and was computed by eating the logs and computing >speedups by dividing raw times. > >2. nodes. Computed from the speedups computed above. I can guarantee that >they would be within less than 1% of the real numbers, because I did some fixed- >depth testing to make sure that calculation was reasonable. > >3. Time. I don't know whether time was computed from 1 above, or whether it >was raw. The paper first only had speedup. I added time/nodes a year later >after one (or more) referees requested it to be compatible with other papers >that did provide them. After talking to my "helper" this afternoon, I realized >that I should have remembered the node issue, because I have only explained >that to you a dozen times in the past 2-3 weeks as you continue to try to make >crafty display data that I have explained can not be displayed. And then you >use that flawed data to draw silly conclusions such as "if you didn't have that >smp lock overhead, and the 44KB copy overhead, you could have gotten a speedup >of > 2. Of course, the fact that your 2 cpu node count was way "understated" >(because of not listening to me about trying to do that in Crafty) didn't deter >you one bit... > > > > > > > >> >>You seem to have you roriginal text of your paper still at home, >>so you must have the logfiles still too? > >I don't have anything "original". Fortunately I had sent several ASCII >copies out before "the crash" and was able to get an ascii version back. >I don't have the log files. I don't have any source except for one version >Harry found, well prior to the singular extension additions. I don't have any >of the carefully saved log files from _every_ game Cray Blitz ever played. I >don't have any versions of Crafty prior to 13.x except for a few sent to me >after I posted a request on r.g.c.c a few years back. > >As I said, I lost _everything_ because the disk crashed and we discovered >that the backups were unusable... Not a big deal although there was a lot >of nostalgia in some of the games that I would have loved to keep "just >because"... > >But of course, I had already told you that I had lost the SE source code when >you asked last year. I had already told you that the log files were gone when >you asked last week. The only reason I have a fair number of old crafty >versions is that I used to keep 2-3 major versions on my ftp site, and >_everything_ on my office machine. Luckily when it went down, the 13.x and >14.x versions were still on the ftp... but it was a big loss. Lots of old >code dealing with null-move threat extensions, early singular extensions >attempts... lots of things I would have liked to have kept... > > > > >> >>Best regards, > >That rings a tad hollow, IMHO. Geeze Bob ! You could have left out this comment.... How the "hey" can you tell. Vincent almost always end with Best Regards...Sounds sincere to me Best Regards Wayne > > > >>Vincent >> >>>On September 03, 2002 at 18:22:04, Dave Gomboc wrote: >>> >>>>On September 03, 2002 at 18:03:14, Gian-Carlo Pascutto wrote: >>>> >>>>>However reasonable your explanations may be, the gist of your DTS article >>>>>and the most important thing for comparison were the speedup numbers. After >>>>>what we discovered and what you just posted, it is clear that they are >>>>>based on very shaky foundations. >>>>> >>>>>What's far worse, until you were directly accused, there was no indication >>>>>whatsoever for all the fiddling that was done with the auxiliary data. When >>>>>you were accused, you denied again, until other people supported Vincent's >>>>>point of view, when you suddenly got an email from an unknown person you're >>>>>not willing to disclose that 'refreshed your memory'. >>>>> >>>>>Additionally, the only other thing to support DTS, you PhD thesis, appears >>>>>to be basically totally unfindable for third parties. >>>>> >>>>>I hope you realize that a request from you to trust your numbers isn't >>>>>very convincing. In fact, with what we know now, I'm pretty sure the >>>>>article would never have gotten published in the first place. >>>>> >>>>>If Vincent wanted to discredit your results, then as far as I'm concerned, >>>>>he's succeeded 100%. >>>>> >>>>>-- >>>>>GCP >>>> >>>> >>>>I don't agree: the main result is the speedup, which was directly measured -- >>>>though I'm certainly not a fan of the estimated node counts being there (at >>>>least without something saying "estimated", which the article may or may not >>>>have done). >>> >>>In this case, Vincent's "your bad memory" would actually be right. >>> >>>The only thing that would have been better would be had he simply asked me >>>specifically what he stated in his first post here. He mentioned a week ago >>>that he thought my data was "faked". I had no idea what he was talking about >>>and I told him _exactly_ what we had done for the speedup stuff.. How I ran >>>the tests, taking pondering into account, etc. Never for a minute thought >>>he was talking about the nodes or times, because he kept talking about the >>>11.1 is fake... >>> >>>He was right and wrong. The 11.1 was _not_ a faked result. But the node >>>counts were definitely calculated because that was the only way I could think >>>of to come up with them. >>> >>> >>> >>>> >>>>But in the main, the least reliable source for information at CCC is Vincent -- >>>>indeed, I'd go so far as to say that whenever he claims something, I tend to >>>>believe that the opposite is true, unless there are some other, more credible >>>>people who agree with him. >>>> >>>>Dave
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