Author: Mridul Muralidharan
Date: 07:58:18 12/26/03
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Comments inline .... On December 25, 2003 at 10:12:11, Robert Hyatt wrote: >On December 25, 2003 at 04:55:44, Mridul Muralidharan wrote: > >>Hi all, >> >> I would like to know the list of MP engines that are currently active - >>amateur , commercial , and private (not in-development efforts :) ) >> >>The list that I could come up with was : >> >>Baron (upto 2 or even higher ? ) >>Brutus >>Crafty >>Diep >>Fritz >>Junior >>Shredder >>Sjeng >>SOS (or is it ParSOS ?) >> >>Of these , which all can scale > 8 procs ? >>Diep I know for sure. >>SOS also I think. >>What about rest ? > >Crafty certainly does, given the right kind of architecture. I've run it >on 32-way boxes for example. Which is this kind of hardware ? I have not seen any results of crafty on a 32 or higher proc box .... Could you give me some link, etc for this ? (And I dont have any data of cray blitz also ...) Thanks > >> >> >>Of these which all are NUMA compatible. >>Latest crafty , Diep. >>Anyone else ? > >Be careful. There is NUMA and there is NUMA. Hmm - fundamentals of design - design for generic case - specialise for specific case :) So if design is to support numa - then max yu need is tweaks for specific hardware - but not much else changes. If you design for smp and try to extend for numa - you are in for shit ! But then , it is pointless to get into this discussion again - we already had this before : You will not agree that crafty design is not good for NUMA and I will not agree to the contrary :) >Current Crafty supports NUMA >under windows, which pretty well limits it to Intel and AMD machines. I could not get crafty to work on aix or irix - otherwise could have given this new numa code in crafty a shot at a 16 or 32 box machine .... but from looks of it - and this is a very personal opinion backed with zero data - it wont scale - atleast nowhere close to your formula given below :) > Diep >is running on SGI, which is not particularly compatible with anybody else. I am sure that diep scales on any other numa platform - remember - teras runs irix which is pretty similar to linux. But this is for Vincent to comment on - not me ! :) >I have an experimental NUMA version of Crafty, but it is not well-checked out >yet (it is a linux version using libnuma for the NUMA stuff, but linux kernels >are very spotty in their NUMA support to date.) > Too true ! Linux is yet to get there ... hopefully next year mid it should be pretty good and stable. >Eventually Crafty will support NUMA on linux and windows. Others may be added >if time permits and hardware becomes available for testing. > Great ! and I assume - with only "tweaks" to get it to work ?!! ;) > > > >> >>Can anyone provide with what is the usual speedup on a Quad for these engines - >>say a typical middle game position ? > >My formula for speedup is this: > >speedup = 1 + (ncpus - 1) * .7 > Thanks for this - do you have an upper limit by which this formula stops being accurate due to diminishing returns ? Also , how much depth does crafty needs to achieve before it starts giving this kindof speedup ? For mess , in the first few plies speedup sucks .... >IE for a quad, that gives 3.1x which is a pretty good approximation. > > > > > >>(In case you need a machine config to base numbers on - what about a Quad Xeon 3 >>GHz 3 Gig RAM running OS of your choice). > >CPU speed really doesn't matter so long as there are no hardware bottlenecks >to deal with. IE my formula above works just as well on my quad pentium-pro >200 as it does on my quad xeon 700 and my dual xeon (with hyperthreading on) >2.8ghz. It also fit the quad opteron 2ghz machine just fine also. This was given just so that I dont get flames like "What hardware" from people who know almost nothing about parallel programming ;) Thanks for your comments Mridul > > > > > > >> >> >>Thanks in advance >>Mridul
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