Author: Robert Hyatt
Date: 18:48:27 04/20/00
Go up one level in this thread
On April 20, 2000 at 17:32:08, James T. Walker wrote: >On April 20, 2000 at 09:09:18, Robert Hyatt wrote: > >>On April 20, 2000 at 01:39:55, Jason Williamson wrote: >> >>>On April 19, 2000 at 23:55:06, Robert Hyatt wrote: >>> >>>>On April 19, 2000 at 23:53:31, Robert Hyatt wrote: >>>> >>>>>As I had mentioned a while back, I have a sack full of quad xeon 550 machines >>>>>in a beowulf cluster. While waiting on a few final pieces to arrive, I decided >>>>>to do what I thought was an interesting test: >>>>> >>>>>two identical machines, and I mean _identical_. Quad xeon 550's, 27 gigs of >>>>>SCSI disks in a raid-0 (striping) configuration, 512mb of ram, etc. IE >>>>>everything is identical, with all the 3-4-5 piece compressed tablebases, >>>>>same opening books, etc. >>>>> >>>>>The only difference was that 'crafty' plays computers and humans, while scrappy >>>>>only plays humans. Several of us had postulated over the years that if you only >>>>>play humans, you can drive your rating through the roof. Using the same >>>>>formulas (5 3 blitz or faster, 60 60 standard or faster, or most any bullet) >>>>>I have been watching the two programs for a month now. And they seem to >>>>>hover at the point scrappy == crafty+100, roughly. Standard has crafty >>>>>actually higher, but that is because crafty is playing standard against >>>>>computers, while scrappy is playing very little standard as humans seem to be >>>>>avoiding that for the most part... and those that do play standard play crafty >>>>>as it is better known. >>>>> >>>>>100 points was a surprise... as I thought it would be more. At present crafty >>>>>is at 31126 and scrappy is at 3219 blitz (which is the most stable ratings >>>> >>>>argh: ^^^^^ >>>> >>>> >>>>3126 of course... >>>> >>>>31126 won't be reached for maybe 10-20 more years. :) >>>> >>>> >>>> >>>> >>>>since >>>>>most games are blitz). >>>>> >>>>>It seems that not playing computers is _not_ a way to grossly inflate your >>>>>rating, unless you consider 100 as inflated. Note that a rating of 3200 is >>>>>very high, considering that there are not a lot of GM players that are rated >>>>>even 3000. I watched scrappy play a 16 game match earlier this week, it won >>>>>8 games, lost one, then one 7 more, for a 15-1 result (5 3 blitz). It lost 32 >>>>>rating points for the effort. :) >>>>> >>>>>I am going to continue the experiment until I get the rest of the beowulf >>>>>hardware (another quad box and a fast ethernet switch to complement the >>>>>giganet switch). If you watch the ratings, you will get a feel for the >>>>>difference in playing only humans and humans + computers... >>> >>> >>>What do you figure your rating gain will be with the beuwolf beast? >> >> >>Difficult to say right now. I am running on a quad xeon. I will be able to >>use 9 machines (total) although really only 8 of them have the giganet inter- >>connect. 8 times the horsepower ought to give a search at _least_ a factor >>of 4 faster, which is conservative I hope. that would be the equivalent of >>doubling the speed 2 times. I would think at least 100 rating points, maybe >>more, but mainly at standard time controls, as distributed computing is not >>going to be great for blitz/bullet... > >Hello Bob, >That's too bad! I was looking forward to seeing that thing take over the world >at blitz! Anyway it will be interesting to watch. Can you give me a couple of >clues as to why the blitz will not work so good? In laymans terms of course. >Regards, >Jim Walker The main reason is that with a blitz game, I am looking at maybe 10 plies for a decent search depth, rather than the normal 13-14 in middlegames. The 10 plies means lots of the parallel searches will be 'small'... and small is bad on a machine where the cost of sending a message might easily be longer than the time required to search the resulting position... I am not sure it won't do well at blitz, so we will see on ICC one of these months. And I am being _very_ conservative with the 4x speedup. I am sure I can get that without any trouble. And I believe that I can possibly get to close to the speedup I get with a normal parallel search, although there are some issues like a global hash table that will take some thought... More as I think about the issues, but right now, I have been so busy ordering equipment for a new lab, and working on being 'non-hackable' on our local network, that I simply haven't done much chess in a couple of months... But I definitely have not 'quit' or 'retired'... :)
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