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Up Topic Rybka Support & Discussion / Rybka Support / Deep (multi-thread) Rybka 4 Aquarium
- - By milrobo [us] Date 2010-05-24 02:36
Does anybody know how many threads it uses? My CPU can handle up to 8 threads.

I presume "deep" means faster. How much faster than non-deep Rybka 4 Aquarium, and does it have any other advantages? What do you get for the extra $$$ ?
Parent - - By insipid (**) [us] Date 2010-05-24 03:39
"Deep" means multiprocessor.  If you buy the non-deep version, it will only use one thread on your CPU.  The deep version will use all of your threads, and is therefore much faster and stronger.

The terminology dates back to the 90's, when very few people had multi-processor systems.  Then there was a premium charged for a version that would take advantage of multiple-CPU systems, which nobody really had, and were only the domain of true hardware specialists.  Nowadays, the ballgame has changed completely, as anybody who has bought a computer in the last 3-5 years surely has a multi-core processor, and therefore benefits from the "deep" version.  To continue selling a single processor version in this environment is really quite silly and is just an excuse to charge much more for a version labeled "deep".  it is an outdated, and frankly disingenuous scheme, but all of the major engines are still doing it, so there it is.
Parent - By Arrière Pensée (Gold) Date 2010-05-24 04:33
Oh, man you will have no trouble running Rybka competitively.
Parent - By mindbreaker (****) [us] Date 2010-05-24 18:38
Right. If there were 2 versions they should be multiprocessor and network.
Parent - - By statistician [us] Date 2010-05-26 02:39
Agree. The silly old "deep" terminology should be put to rest for good, and there should be only one version (of course, multithreaded) - not just Rybka, every engine out there.
Lets move on.
Parent - By Uly (Gold) [mx] Date 2010-05-26 04:23
"Deep"'s original reference comes from Deep Thought, the computer that gave 42 as the answer to the ultimate question of life, the universe, and everything from The Hitchhiker's Guide to the Galaxy. I don't see any problem with this reference.
- - By milrobo [us] Date 2010-05-24 13:50
Thanks Insipid and Sidserious. I see the beta users are having a discussion (argument) about whether or not 8 cores is necessary to run Rybka at full strength. What do you think?
Parent - By mindbreaker (****) [us] Date 2010-05-24 19:54
With every ply there is a significant chance the engine will find a better move.  So the more cores the better.  In practice in normal one-line mode it rarely changes after 45 minutes on my 4-core 3500mhz machine. That could be an illusion.  If it isn't, then, in theory, 64 fast threads with proper communication should be able to reach this level in a game with 3 min per move. But I am only talking about R3.  R4 might behave differently.  In muli-line R3 is more apt to discover a better move during long thinks and I still have changes after 24 hours of it sitting on a position but you have to max out the RAM.

Obviously, we don't have 64-thread machines yet.  I think the best you can do is 48 at about half the comparable processing per thread: http://www.tyan.com/product_SKU_spec.aspx?ProductType=MB&pid=670&SKU=600000180  The cloud (series of networked computers that can process together) version is not available.  Cloud computing is much less efficient because of poor communication between cores and a lot of processing is redundant.  Maybe in 3 years state-of-the-art will reach that 64 core level. But R4 is a whole new ball game.

Even so how many people actually run their machines at 3 min a move.  It is more like 3 min per game.  That would require truly massive processing to reach that level.  5 sec per move...hmm...2,880 cores if my math is correct.  Well, that is past R3's max threads so they would have to be faster threads to get the number down.  What 20 years?  Who would even care?  We will all be running Rybka 4.1 and waiting for Rybka 5 ;)

Well, in 20 years the engines will all be different...AcidBath 5, InterglacticSneeze 8, FrogTongue 3.3, RybkaWho? 7...
Parent - By statistician [us] Date 2010-05-26 02:48
Well, "full strength" is relative to whatever resources your computer has. It is not an absolute term.
If a cpu has 6 cores and can run 12 threads, and you use them all, that's full strength.
If another cpu has only one core that can run only one thread, and you run one thread, that is full strength too.

Of course, memory bandwidth, caches and GHz are all part of the "strength", but we are focusing on cores here.
Up Topic Rybka Support & Discussion / Rybka Support / Deep (multi-thread) Rybka 4 Aquarium

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