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Topic: Usage of 2, 4, 8 cores? (Read 6686 times) |
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Fritzlein
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Re: Usage of 2, 4, 8 cores?
« Reply #15 on: Sep 23rd, 2008, 6:13pm » |
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Thanks for spelling it out. The example of one thread reading what another has partially written is illuminating, and incidentally shows how the legal move test wouldn't help.
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| « Last Edit: Sep 23rd, 2008, 6:13pm by Fritzlein » |
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Janzert
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Re: Usage of 2, 4, 8 cores?
« Reply #16 on: Sep 23rd, 2008, 9:37pm » |
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Right, the illegal move check doesn't guard against invalid data. It's just the part adds the almost to the "almost ignore the problem" method.  It just guards against using data that is likely to have a catastrophic effect on the program's operation.
Janzert
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nbarriga
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Re: Usage of 2, 4, 8 cores?
« Reply #17 on: Sep 24th, 2008, 11:36am » |
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on Sep 21st, 2008, 9:36pm, 99of9 wrote:One afternoon I tried to parallelize Gnobot. Unfortunately I have much to learn, because while it utilized both cores, it actually slowed down. I was going parallel at the leaf nodes (in the evaluation function), but it seems I need to do it higher up the tree.
Does anyone know an easily implemented parallel search algorithm? Even better, would anyone care to parallelize Don Dailey's sample bot? |
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I think the easiest way to do it(and i think it would work pretty well) is just do a normal 1 step search first, and then assign 1/N of the generated new positions to each of the N processors. Basically having an independent alpha-beta search for each processor. I would try first using independent hash tables also, for simplicity.
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Janzert
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Re: Usage of 2, 4, 8 cores?
« Reply #18 on: Sep 24th, 2008, 3:10pm » |
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Young Brothers Wait should be about as easy to implement and is suppose to have quite a bit better performance.
Janzert
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fotland
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Re: Usage of 2, 4, 8 cores?
« Reply #19 on: Dec 14th, 2008, 11:29pm » |
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Bomb only uses one core. When I wrote it I only ahd a single core machine, and parallel alpha-beta is more complex.
David
on Sep 21st, 2008, 9:36pm, 99of9 wrote:I don't know why I didn't notice this thread when it was active, but I asked the same question of Fritz a few weeks ago. He was surprised that Gnobot does not utilize multiple cores, and was pretty certain that bomb does. Jeff also mentioned that clueless does.
The reason I raised the topic was that like arimaa_master, I think it is going to be increasingly important to the bot championship (and eventually the challenge).
One afternoon I tried to parallelize Gnobot. Unfortunately I have much to learn, because while it utilized both cores, it actually slowed down. I was going parallel at the leaf nodes (in the evaluation function), but it seems I need to do it higher up the tree.
Does anyone know an easily implemented parallel search algorithm? Even better, would anyone care to parallelize Don Dailey's sample bot? |
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arimaa_master
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Re: Usage of 2, 4, 8 cores?
« Reply #20 on: Dec 15th, 2008, 2:48am » |
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on Dec 14th, 2008, 11:29pm, fotland wrote:Bomb only uses one core. When I wrote it I only ahd a single core machine, and parallel alpha-beta is more complex.
David
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Wow, so clueless is actually the ONLY ONE using multiple cores? If so - It will have the more and more important hardware advantage over his competition (maybe this year if quad will become in 1000 bucks horizon).
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99of9
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Re: Usage of 2, 4, 8 cores?
« Reply #21 on: Dec 15th, 2008, 5:33am » |
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As of today, Gnobot is parallel! So far it's only giving me about a 20% gain (on a dual core), and I don't have any collision protection, but it's a start.
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Fritzlein
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Re: Usage of 2, 4, 8 cores?
« Reply #22 on: Dec 15th, 2008, 6:47am » |
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Very cool, 99of9. What speedup do you expect on four cores? I guess you will have a chance to test once you get an account on the tournament machines. (assuming quad core comes in the price range this year)
Fotland, thanks for clarifying that Bomb is not parallel. I must have dreamed that up myself. I apologize for misleading the other developers about that.
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| « Last Edit: Dec 15th, 2008, 6:57am by Fritzlein » |
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arimaa_master
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Re: Usage of 2, 4, 8 cores?
« Reply #23 on: Dec 15th, 2008, 7:48am » |
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on Dec 15th, 2008, 5:33am, 99of9 wrote:| As of today, Gnobot is parallel! So far it's only giving me about a 20% gain (on a dual core), and I don't have any collision protection, but it's a start. |
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Congrats Toby!
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aaaa
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Re: Usage of 2, 4, 8 cores?
« Reply #24 on: Dec 15th, 2008, 8:13am » |
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on Dec 15th, 2008, 2:48am, arimaa_master wrote:| Wow, so clueless is actually the ONLY ONE using multiple cores? |
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Actually, if I am remembering this correctly, it isn't Clueless that is parallel, but Jeff's endgame database generator, so we just have our first now.
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Janzert
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Re: Usage of 2, 4, 8 cores?
« Reply #25 on: Dec 15th, 2008, 12:43pm » |
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Right, I think I was the one misleading people about clueless being parallel. 
Janzert
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99of9
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Re: Usage of 2, 4, 8 cores?
« Reply #26 on: Dec 15th, 2008, 2:07pm » |
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on Dec 15th, 2008, 6:47am, Fritzlein wrote:| What speedup do you expect on four cores? I guess you will have a chance to test once you get an account on the tournament machines. (assuming quad core comes in the price range this year) |
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No idea sorry Fritz. There are improvements I need to make before I can do any serious performance testing.
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Fritzlein
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Re: Usage of 2, 4, 8 cores?
« Reply #27 on: Dec 15th, 2008, 2:33pm » |
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on Dec 15th, 2008, 2:07pm, 99of9 wrote:| No idea sorry Fritz. There are improvements I need to make before I can do any serious performance testing. |
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Congrats anyway on being the first to have this feature. The only downside is that if you win the Computer Championship, everyone will think it is due to parallelism, rather than being due to your excellent evaluation function.
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99of9
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Re: Usage of 2, 4, 8 cores?
« Reply #28 on: Dec 15th, 2008, 2:49pm » |
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Maybe they'll be right! However, I expect both opfor and clueless to be parallel by then - i wanted to start putting the pressure on so that all 3 will be humming louder than bomb.
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omar
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Re: Usage of 2, 4, 8 cores?
« Reply #29 on: Dec 15th, 2008, 9:09pm » |
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Toby,
Congratulations on paralleling GnoBot. I am anxious to see how it does against Bomb2005. What's the specs of the machine are you running it on locally?
This years system will most likely also be a Intel Core 2 Duo, but faster clock speed than last year.
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| « Last Edit: Dec 15th, 2008, 9:10pm by omar » |
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